Stephen James Orr v Cobar Management Pty Ltd - [2019] NSWDC 224 - NSWDC 2017 case summary — Zoe

NSWNSWDC

Stephen James Orr v Cobar Management Pty Ltd

[2019] NSWDC 224

District Court of NSW|2017-11-24

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At a glance

Source facts

Court

District Court of NSW

Decision date

2017-11-24

Catchwords

CRIME - prosecution - work health and safety - duty of persons undertaking business - duty of employers - risk of death or serious injury - death of worker

Source

Original judgment source is linked above.

Catchwords

CRIME - prosecution - work health and safety - duty of persons undertaking business - duty of employers - risk of death or serious injury - death of worker

Judgment (67 paragraphs)

[1]

Solicitors: McCulloch Robertson (NSW Department of Industry, Skills and Regional Development) Seyfarth Shaw (Defendant) File Number(s): 2016/174236 Publication restriction: None

[2]

TABLE OF CONTENTS TABLE OF CONTENTS Judgment Introduction Facts General background The dewatering system Sumps Drain holes Strainers Large capacity pumps The organisation of mining activities The safety procedures at the mine The Mine Safety Management Plan (MSMP) The MOC Procedure The CSA Controls The CSAfe Procedure The JSA Procedure Safe Work Procedures Drug and Alcohol Policy Safety topic of the month Enforcement of Safe Work Procedures The Health Safety Environment and Training Department (HSET) Regular Inspections by a dedicated Mines Inspector General practices in relation to sumps prior to the incident Events leading up to the incident The 8670 Pump Station Project Events of 11 June 2014 Evidence of Anthony Gaydon Evidence of James Russell Evidence of Tony Chaplain Evidence of Terry Roberts Evidence of Jamie Baber Evidence of Dan Howard Evidence of Robert Cownie Evidence of Kenneth McMillan Evidence of Gavin Booth Findings of fact relating to the incident Events after the incident The Manager's Specific Instruction - Working in and Around Sumps Events of 16 June 2014 The autopsy report The Sump Procedure The elements of the offence The relevant law consideration Element 3 - Did the defendant fail to comply with its health and safety duty by failing to take the steps particularised in [6] of the Summons? The pleaded risk The likelihood of the risk occurring The degree of harm The defendant's knowledge of the risk and the ways of eliminating or minimising the risk The defendant's knowledge of the pleaded risk Was the pleaded risk reasonably foreseeable? Mr McMillan's instructions at the pre-shift meeting The particulars of breach [16] Of the Summons [17] Of the Summons [18] Of the Summons [19] Of the Summons Conclusion on Element 3 Element 4 - Did the defendant's breach of duty expose Mr Hern to a risk of death or serious injury? Causation The intoxication issue The Evidence of Dr Judith Perl Evidence of Dr Michael Robertson Consideration of the Intoxication Issue Conclusion on Element 4 Conclusion and Orders

[4]

General background

The mine is an underground metalliferous mine. It is one of the deepest mines in Australia, with workers operating at a depth of up to 1600m below the surface. The underground conditions in the mine were affected by its geology, in particular, the operation of horizontal stress fields and the mining operations including working on different levels simultaneously, the use of drilling equipment and the use of explosives. These factors produced a dynamic environment within the mine that could not always be reliably predicted.
The process of extracting copper ore from the mine was achieved by drilling holes into the earth (stope holes) and placing explosives in these holes. Some of the explosives came in a liquid or gel form, which were held in place by inserting blast bags into the holes. Blast bags were made of plastic and could be inflated with an air hose or were self-inflating. The self-inflating blast bags contained a gas cylinder in them. The gas would be released by pressing a button on the bags; once to cause the bag to inflate rapidly or twice to cause the bag to inflate more slowly.
The mine operated in two 12 hour shifts. At shift cross-over in the morning and evening all workers were required to leave the mine. At this time the explosives would be detonated. The rock released by the explosives would be removed by remote control loader and sent for processing. The area opened up by the removal of the rock would be shored up by the installation of steel reinforcing mesh on the walls and ceilings which were sprayed with shotcrete. The shotcrete was a mixture of cement, water and plastic fibres about 25mm in length (plastic fibres). The plastic fibres were added to the shotcrete to strengthen it. When all the rock was removed, the area that had been opened up was backfilled with a mixture known as 'paste', which was comprised of crushed rock, the by-product of processing, and cement.
The mine consists of a helical roadway known as the decline, which has access points to each level of the mine. Workers go underground by riding in a cage down a shaft to 9 Level or by driving light vehicles from the surface down the decline to the bottom levels of the mine. Most workers travelled to 9 Level by cage and then proceeded further down the mine in light vehicles, because it was quicker to do so. The trip from the surface to 9 Level in a light vehicle took about 40 minutes, because the light vehicles were speed limited.
The different levels of the mine were referred to by their metres reduced level measurement (mRL), but some were referred to by the historical position of the level, including 4 Level, 9 Level (9450mRL) and 11 Level (9280mRL). The lower the mRL, the further down the mine the level was. The opposite was true of the historical levels, with 11 Level being the furthest down the mine.

[9]

Large capacity pumps

At the lower levels of the mine, a series of pumps pumped water to the 8855 Level where there was a dam. From there the water was pumped to the 9 Level, where large pumps then pumped the water to the 4 Level and then to the surface. The pumps at the lower levels of the mine were less efficient because they had to work against increased gravitational pressure of the water (head pressure).
At the 8855 Level there were two Wilson Snyder pumps and one Mono pump. The Wilson Snyder pumps pumped water up from the dam on the 8855 Level through to two rising mains to the 11 Level, while the Mono pump pumped water to the 9040 Level. The water entering the dam was very turbulent and muddy and did not have time to settle before being pumped up to the higher levels in the mine. The Wilson Snyder pumps on the 8855 Level were pumping dirty water causing premature wear on the rubber seals of the pumps. These pumps were particularly prone to failure. A sump on the 8855 Level caught any water that overflowed from the dam as well as leakage from the three pumps. The water from that sump drained via a drain hole to the 8820 North sump.
The mine also used Warman pumps at various levels in the mine. A Warman pump was attached to a 1000 litre tank that would store the water pumped until it reached capacity. The water would then be pumped out of the tank by an outlet hose. There were references in the evidence that a Warman pump could be used as a portable pump. The evidence did not disclose the size or weight of a Warman pump, but I infer that it would be quite heavy, especially bearing in mind that it could hold 1000 litres or 1 tonne of water.
The fixed plant maintenance team looked after the underground pumping systems at the mine. This consisted of preventative maintenance tasks in relation to pumps as well as repairs. From about March 2013, a split inside one of the rising mains rendered the #1 Wilson Snyder pump at the 8855 pumping station, non-operational. The fixed plant maintenance team attempted to repair the rising main in March 2013 using shotcrete but were unsuccessful. The repair of the rising main was difficult because the split was between levels in a place that could not be readily accessed. The installation of a new rising main involved drilling a hole over a considerable distance. Options for redirecting the #1 Wilson Snyder pump were investigated but not implemented prior to June 2014.

[10]

The organisation of mining activities

In June 2014, workers in the underground production and development team were assigned to four mining crews (A, B, C and D Crew) that worked on a rotating four day on, four day off roster system. Each crew was supervised by a shift supervisor (supervisor) who reported to the shift foreman (foreman). A supervisor worked the same roster as their crew. Foremen were employed at the mine on a rotating eight day on, six day off roster, with an overlapping one day hand-over period. Accordingly, the foremen supervised different supervisors and crews from time to time. The foremen reported to the production manager, Dan Howard.
In or about December 2013, the defendant undertook a restructure of its workforce. At that time, each day shift was supervised by a production and a development supervisor together with a foreman. The restructure amalgamated the positions of the production supervisor and development supervisor and placed a supervisor and foreman on each shift. This change increased the number of personnel for whom each supervisor was responsible, but workers were able to contact the foreman via radio if the supervisor was unavailable. The role of supervisors was to balance the aims of managing safety and achieving targets. This involved giving directions to crew members and others working underground, including contractors. Foremen were responsible for monitoring compliance with safety standards, co-ordinating crews and shift changes and monitoring ongoing projects and upcoming jobs.
Prior to the start of each shift, the outgoing supervisor conducted a hand-over with the incoming supervisor, the purpose of which was to update them on the work that had been completed during the shift and the conditions within the mine. This occurred over the telephone, with the outgoing supervisor underground and the incoming supervisor on the surface.
The outgoing foreman prepared a foreman's shift plan containing details of the work to be completed during the next shift. This was a rolling document that was updated after each shift to reflect changes, new tasks and priorities. The outgoing foreman conducted a handover with the incoming foreman in the foreman's office on the surface before the commencement of each shift. The handover included going through the foreman's shift plan, item by item. The oncoming foreman would also go through the foreman's shift plan and provide a copy of it to the oncoming supervisor in the foreman's office on the surface, before the pre-shift meeting with the crew. The foreman's shift plan included general safety information and specific information for each task identified in it.
The supervisor's role was to execute the elements of the plan involving their crew. The supervisor would prepare a daily shift plan (PLOD Sheet) which set out the roles to be performed and listed the personnel from both the outgoing and incoming crews who were allocated to those roles. Copies of the PLOD Sheet were provided to the crew and contractors during the pre-shift meeting. The pre-shift meeting went for 20 - 45 minutes and included reminders about various safety procedures in the form of a 'safety topic of the month'. Occasionally the foreman attended pre-shift meetings if they needed to communicate information to the whole crew. The PLOD Sheet provided only a general outline of the work tasks or roles to be performed, for example driving the water truck. It was possible that the tasks or roles outlined on a PLOD sheet would become irrelevant when the workers went underground because priorities changed. PLOD sheets did not set out the manner in which workers were to carry out their job but it was expected that workers would comply with the defendant's safety procedures when completing the allocated tasks. The PLOD sheet sometimes contained information intended to be communicated to all of the workers underground.
At the end of each shift, workers on the outgoing crew returned to the surface, where each member was required to liaise with the incoming crew member who had been assigned to take over their tasks (the cross-shift meeting). The cross-shift meeting took place on the surface in an area outside the muster room, immediately after the pre-shift meeting. The cross-shift meeting was intended to provide an opportunity for information to be passed on between the workers who were responsible for the relevant tasks or roles identified on the PLOD Sheet.

[13]

The MOC Procedure

On 13 August 2013, the defendant adopted the MOC Procedure intended to apply to temporary and/or permanent changes to activities, infrastructure, products and services. The purpose of the MOC Procedure was to maximise improvement opportunities while minimising risk. The MOC Procedure was intended to ensure that adopted changes provided the intended benefits without unknowingly compromising health, safety or the environment. A fundamental aspect of the MOC Procedure was to conduct risk assessments and to put in place risk controls. The MOC Procedure applied to physical engineered changes as well as procedural and organisational changes.
A change was defined to be any modification, alteration or substitution to a system, process, plant or equipment. The definition excluded normal repairs to restore original functionality, state and configuration of equipment or a system utilising identical procedures, resources or components. Examples of changes included in the procedure were the bypassing or disabling of components or systems that would normally be in operation, any physical change or change in the method of operation and any new changes to procedures, non-routine work, safe work plans, practices and standards or guidelines.
The MOC Procedure stated that changes to physical plant would not include the replacement of worn or damaged equipment with a newer machine of the same specification.
Sheldon Wilson, one of the foremen, gave an example of a process to which the MOC Procedure was applied as the replacement of the haul trucks used underground in the mine with a different make of haul truck. The MOC Procedure was applied to assess whether the conditions underground were suitable for the use of the new haul truck, including taking measurements of the clearances underground, preparing a training package for the truck drivers to enable them to be trained on the operation of the new trucks and the identification of new processes required to service and maintain the new trucks.
The requirement for a risk assessment depended upon the nature and potential impact on the business. A sufficient risk assessment may be the completion of a JSA, but depending on the impact, a formal risk assessment or a specialist team formal risk assessment may be required. The preparation of a JSA was the minimum level of risk analysis provided for by the MOC Procedure.
The prosecution case was that the MOC Procedure was never applied to the processes involved in the 8670 Pump Station Project, which I will return to.

[16]

The JSA Procedure

The JSA Procedure required the workers to ensure that they conducted a JSA when required and in accordance with the JSA Procedure, to actively participate in the development of a JSA, to follow the JSA while undertaking the task and to report any matters that could have been improved or any residual risks that remained after the implementation of the JSA controls.
The JSA Procedure required supervisors to ensure that all workers were trained in the JSA Procedure, that workers undertook JSAs when required by the JSA Procedure, to sign off on the JSA as an acknowledgement that the hazards involved in the task were identified and that the implemented controls were reasonable and effective in reducing the risk to an acceptable level within the risk matrix.
A worker was not required to complete a JSA for a Standard Job if the worker had been assessed as competent in the task as part of a training program. A Standard Job was defined to be: Jobs for which the tasks involved are detailed and the hazards and controls are already defined because it has a procedure, instruction, training package, or similar accepted document and the person performing the task is trained and assessed as competent.
The environment could have an impact on a Standard Job and was required to be considered when determining if a JSA was required.
Non-standard Jobs were defined as those for which there were no training packages or procedures and a JSA was the minimum requirement for those jobs.
A JSA was sometimes required for a Standard Job that was done infrequently. For example, where the worker had not done the job for some time and was unfamiliar with the steps involved or the risks posed and where the environment could change during the performance of the job.
A JSA required the listing of the steps involved to complete the job, the identification of the hazards involved with each step and the identification of the controls to be implemented for each hazard. The residual risk was then assessed against the risk matrix.
A completed JSA was then submitted to a supervisor for approval. Once approved, each worker would then sign the JSA to indicate that they understood it and that they would be adhering to it during the course of the work.
The supervisor was required to consider if all of the steps, hazards and controls had been correctly identified, that the risk scores were reasonable and the residual risk sufficiently low to allow the work to proceed.

[21]

The Health Safety Environment and Training Department (HSET)

The defendant's safety system was administered by the HSET. The HSET's responsibility was to implement health, safety and environmental systems, to train the workers on those systems, to maintain a record of the systems and training and to improve the systems in place. The HSET conducted training, performed inspections and audits, reviewed documented policies and updated them when required.
Tanya Gilbert was the Manager of the HSET from December 2011 and was one of the management team at the mine, reporting directly to the Chief Executive Officer, Deon Van Der Mescht. Ms Gilbert liaised with the managers of the other departments, particularly Mr Howard, on a daily basis. Ms Gilbert also liaised with the regulatory authorities on behalf of the mine, including preparing the responses to the section 155 notices issued in relation to the investigation of the incident.
The documented systems in place at the mine at the time of the incident were exemplary. The documents were expressed in clear and simple language that could be and was understood by the workers they applied to. The content of the training packages in evidence was similarly impressive. Further, the mine had kept comprehensive records of the training that each worker had undertaken and the dates on which the training competency would lapse. This information was computerised and linked to the worker's access card to prevent access to the site if certain training had not been undertaken by a critical date. In those circumstances, arrangements would be made for the worker to undergo further training before being permitted onto the site.
Ms Gilbert was a very impressive witness who ably demonstrated how the documentary systems were implemented in practice and how the training of the workers was undertaken. It was clear from Ms Gilbert's evidence that the system provided areas of overlap and multi-layering to achieve its aims. I am satisfied on the basis of Ms Gilbert's evidence, the records and the evidence of the workers in general on this topic, that the safety systems contained in the documents referred to in the evidence were actively and conscientiously implemented in the day to day activities of the mine by the workers and supervisory staff.

[23]

General practices in relation to sumps prior to the incident

Strainers and drain holes occasionally became blocked with mud and other debris, including plastic fibres, causing water to build up in sumps. From about 2008, when the defendant first started using plastic fibres in the shotcrete, the need to clear them from strainers was a recurring issue in the mine below the 11 Level where shotcrete was used.
It was necessary to monitor strainers inserted in drain holes to make sure they did not become blocked. If the drain hole was easily accessible from the roadway close to the top of the sump, a strainer could be approached on foot and cleared by hand or using a pelican pick. A pelican pick was a type of crowbar with a hook on the end of it.
This type of task often fell to Terry Roberts. Mr Roberts was a back-fill technician with additional duties to monitor strainers for blockages. Mr Roberts had ordered and received a set of waders for use in doing this work. If Mr Roberts could see the strainer in the drain hole he would approach it on foot and clear the strainer by hand or using a pelican pick. Mr Roberts gave evidence that he would not approach a drain hole if he could not see the strainer because the water level was too high, or if it was missing from the drain hole. In those situations, Mr Roberts gave evidence that there was no protection against the risk that a part of his body could be sucked into the drain hole by the force of the water. The waders used by Mr Roberts were usually hung on the back of his light vehicle or hung up outside the 11 Level supervisor's office. Mr Roberts believed, and there was evidence from other witnesses, that it was generally known that Mr Roberts wore waders from time to time. The removal of fibres from strainers in drain holes and sumps was a task that was done on a daily basis by Mr Roberts and/or other workers who went past a sump and identified a blockage.
Other workers would approach strainers with relatively high levels of water on them in the basket of an ITC. An ITC was a piece of heavy mobile plant with a basket on the front that could be raised or lowered by hydraulics. An ITC was used to lift heavy pieces of equipment, as well as to raise workers in the basket to various heights for the purpose of undertaking different tasks. The ITC would be driven close to the strainer to allow it to be removed from the drain hole or cleared with a pelican pick.
There were other occasions in which a sump drain hole would become completely blocked by a combination of dirt and rock, though this was not a common occurrence. Mr Roberts was usually allocated the task of unblocking the drain hole, in those circumstances. He estimated that he did so once or twice per year for about the 10 years prior to the incident. Mr Roberts described a number of methods used to deal with a blocked drain hole. First, workers could use water and compressed air to release a blockage from the level below the sump. This involved using an ITC basket from the level below, feeding a pipe up through the drain hole until it reached the blockage, filling the pipe with water and then using compressed air to propel the water in a jet towards the blockage in order to release it. It was also possible to use this method from the level above. Second, workers on occasions used explosives to blow out a blockage. PVC pipe would be used to feed the explosive up to the blockage through the drain hole. The explosive was then detonated breaking up the blockage. This method was used if air and water were not available to carry out the first method. When drain holes were too deep for blockages to be reached from underneath, explosives could be used to remove the blockages from above. Third, chains attached to the roof or wall of a sump were placed inside drain holes which allowed accumulated material inside the holes to be loosened by agitating the chains.
If the water level in a sump was high enough to submerge the strainer, workers would reduce the depth of the water before using one of the methods above to unblock the drain hole. This was usually done by pumping water out of the sump using a pump. Flygt pumps were lowered into the sump from an ITC basket and attached to the roof by use of a chain. An outlet hose would be attached to the pump which would pump water into another sump or into a Warman tank.
Tony Walkinshaw, a member of the services crew and the Mines Rescue Captain, gave evidence that about a week before the incident he had unblocked a blocked strainer in a sump by removing it with a loader. The water level had got to a height over the strainer, which was hopelessly blocked and stuck in the drain hole by the water pressure. The workers used a loader to forcibly remove the strainer from the drain hole, causing the water to swiftly and loudly evacuate down the drain hole. Mr Hern was present during this task.
Mr Roberts gave evidence that he filled out a CSAfe form for every unblocking task he had completed. He did not believe that the use of water and compressed air gave rise to a hazard that he could not control. He filled out JSAs for unblocking a drain hole when using explosives.
The evidence of the workers was that a sump should not be entered when the water level was high, particularly if the strainer was not visible. The workers gave evidence that the method chosen to unblock a drain hole should take into account the size of the sump and the depth of the water present. It was possible to reduce the depth of the water by pumping it down the decline or to another sump before clearing the blockage.
It was occasionally necessary to block drain holes deliberately so that work could be undertaken on the level beneath the relevant sump. On occasion workers used plastic ANFO bags or vent bags to block drain holes. ANFO bags were plastic bags in which explosives were supplied to the mine. Vent bags were plastic sheeting that was used to pump air into different parts of the mine for ventilation. Methods of blocking drain holes included making a plug out of rocks and dirt inserted in the plastic which was then wrapped in a chain and put in the drain hole. The end of the chain would be attached to the roof of the sump so that the chain could be used to remove the bag from the hole when it needed to be unblocked. On other occasions blast bags had been used to block a drain hole. Tony Chaplain, a foreman, gave evidence that in his experience when a blast bag was used, the strainer would be placed in the drain hole on top of it to flag the location of the drain hole. The deliberate blocking of a drain hole occurred less frequently than the random blocking of a drain hole by mud, rock and debris.

[24]

The 8670 Pump Station Project

In or about December 2013, plans were implemented for the installation of a major pump station at the 8670 Level, to replace some of the smaller pumps that transported water up to the 8855 Level. The 8670 Pump Station Project, involved drilling additional drain holes in sumps on the 8790 and 8730 levels to allow water to flow down to the pump station at the 8670 Level, the creation of a cuddy to house two Mono pumps to be installed at the 8670 Level and the creation of a sump at the 8670 Level to collect the water to be pumped up by the pump station.
A series of planning meetings were held to develop the project between various department representatives, commencing in December 2013. There was no consideration given to the MOC Procedure during these meetings.
A drain hole was required to be drilled from the 8790 North sump down to the 8760 Level. On or about 30 May 2014, Nicholas Fryer, a production engineer prepared a design of the drain hole that was documented in plans and information sheets to set aside time for the use of the drill rig for this purpose. Mr Chaplain was responsible for executing the plan to drill the drain hole.
In order to drill the drain hole in the 8790 sump, the drain hole from the 8820 North sump had to be blocked, to prevent water draining to the 8790 Level and coming into contact with parts of the drill rig that were powered by high voltage electricity. In or about early June 2014, Mr Fryer and Mr Chaplain discussed using blast bags to block the 8820 North sump drain hole to prevent water flowing through it. Mr Fryer considered this to be the best method for blocking the 8820 North sump, because the blockage could be easily removed by puncturing the blast bag with a scaling bar. A scaling bar was a long crow bar used at the mine. Mr Fryer anticipated that the drain hole could either be accessed on foot or in an ITC depending on the height of the water. In his view if the water level was very high a pump could be installed to lower the water level before removing the blockage. Mr Fryer and Mr Chaplain did not discuss any safety issues arising from proceeding in this fashion, at that time.
On 6 June 2014, Sheldon Wilson was rostered on as the day shift foreman. At the end of the day shift, he had a discussion with the night shift foreman, Joe Patten and a night shift supervisor, Matt Bennett, regarding the need to block the 8820 North sump drain hole. They agreed that the sump would be cleaned out thoroughly, and that a flygt pump would be installed in the sump with an outlet pipe attached to ensure that the water level and sump could be managed. They agreed that the strainer should be removed before blocking the drain hole. Mr Wilson, Mr Patten and Mr Bennett discussed several options for blocking the sump including the use of ANFO bags wrapped in chains, blast bags or hessian bags wrapped in wire. They did not make a final decision as to which method would be used, leaving this to the discretion of the relevant shift supervisor and operators to whom the task was allocated.
During the 7 June 2014 day shift, Robert Job and Mark Clynes extended a pump line to the 8820 North sump using a 110mm poly pipe. They bogged out the sump with a loader and installed a 20kW electric flygt pump in the sump. At the time, they did not have the necessary fitting to connect the pump to the outlet pipe. Mr Job saw a strainer in the sump drain hole which he did not remove during or after the installation of the pump. Mr Clynes recalled marking the location of the 8820 North sump drain hole on the wall with orange paint after he had bogged out the sump.
At the beginning of the night shift on 7 June 2014, Mr Bennett allocated Greg Black the task of blocking the 8820 North sump drain hole using blast bags. Mr Bennett and Mr Black had a discussion about the task. Mr Black did not complete the task during the course of the shift because he was preoccupied with other duties.
On the day shift of 8 June 2014, Mr Wilson was the shift foreman and Blake Dunne was the shift supervisor. At the handover meeting from the night shift, neither Mr Bennett nor Mr Patten could confirm whether the 8820 North sump drain hole had been blocked although they believed that this had probably not occurred. Mr Job and Mr Clynes were allocated the task of blocking the 8820 North sump drain hole during the day shift of 8 June 2014. Mr Job recalled that at the cross-shift meeting he was told to use blast bags. Mr Job and Mr Clynes had used blast bags previously to contain explosives within stope holes, but neither of them had blocked a drain hole using a blast bag. Neither recalled having a conversation with Mr Dunne or Mr Wilson about how the task should be carried out, how long the drain hole would be blocked for, or how it would be unblocked.
Mr Job and Mr Clynes collected several self-inflating blast bags from the 9015 magazine before travelling to the 8820 North sump to block the drain hole. When they arrived, the sump was dry and the strainer was in the drain hole. They attempted to insert a blast bag into the lower narrow part of the strainer but realised that this would not effectively block the drain hole as the strainer did not sit flush with the collar of the drain hole once it was in position. They then inserted a blast bag into the drain hole and inflated it but realised that the inflated blast bag would not expand to fill the diameter of the drain hole. They then inserted an inflated second blast bag alongside the first. They did this by holding the blast bags in place inside the drain hole as they inflated. Based on their visual assessment of the hole Mr Job and Mr Clynes believed that the two bags would effectively seal off the sump drain hole. There was no water in the sump at that time.
Mr Job gave evidence that he and Mr Clynes inserted the blast bags about 150mm from the top of the hole as this was a convenient distance from where to reach into the hole while holding the bags. Mr Clynes believed that the bags were flush with the top of the drain hole. They left the strainer leaning against the mine wall near the drain hole because it was not possible to insert it into the drain hole on top of the blast bags. Neither Mr Job nor Mr Clynes recalled discussing completing the task with Mr Dunne or Mr Wilson although as a matter of usual practice, they would have done so. Mr Job completed a CSAfe form for the task of blocking the 8820 North sump drain hole.
By the end of the day shift on 8 June 2014 Mr Wilson had been informed that the drain hole had been blocked. He was not aware who had carried out the job, whether it had been completed during the day shift or the previous night shift, or by which method it had been done. At the foreman shift handover meeting Mr Wilson informed Mr Bennett and Mr Patten that the drain hole had been blocked.
During the foreman's handover meeting on the morning of 9 June 2014 Mr Patten and Mr Wilson discussed the water level in the 8820 North sump. Mr Wilson was informed that the installed pump was operational, and the water was at a manageable level. Mr Wilson, Mr Patten, Mr Bennett and Mr Russell had various discussions with one another about maintaining the water level in the 8820 North sump and checking the pumps regularly.
On or about 9 June 2014, Mr Roberts drove past the 8820 North sump as he was checking the backfill lines and noticed there was no strainer in the drain hole. The strainer was leaning against the wall. Mr Roberts attempted to insert it in the drain hole but was unable to do as there were two inflated blast bags blocking the hole around 6 inches from the top. Mr Roberts had not previously seen blast bags used to block a drain hole in this manner.
On 9 June 2014, Mr McMillan took over from Mr Bennett as the night shift supervisor. During the night shift Mr McMillan drove past the 8820 North sump and saw that the strainer was not in place over the drain hole. Mr Patten told him that it had been blocked so that work could be completed on the 8790 drain hole. Mr McMillan stated that the sump contained no water at that time.
The drain hole from the 8790 sump to the 8760 Level was completed by the time of the foreman's handover meeting on the morning of 10 June 2014, prior to the commencement of the day shift. As further work needed to be undertaken on the 8670 pump station, Mr Patten and Mr Wilson decided to leave the 8820 North sump drain hole blocked to ensure water did not flow down through the mine to the 8670 Level and potentially interfere with electrical equipment. It was anticipated that the 8820 North sump drain hole would remain blocked for a couple of days until work on the 8670 pumping station had been completed. They did not discuss methods for unblocking the 8820 North sump drain hole. During his handover with Mr Chaplain, Mr Wilson communicated that the 8820 North sump drain hole had been blocked by an inflatable bag and the importance of monitoring the water levels.
On 10 June 2014, Mr Chaplain travelled past the 8820 North sump at some time during the afternoon. He noticed the water was within the confines of the sump and was at a manageable level. He believed he saw the strainer in place over the drain hole but did not approach the sump to take a closer look.
At the foreman's handover meeting on the evening of the 10 June 2014 Mr Patten and Mr McMillan discussed the need to monitor the 8820 North sump. During that night shift Mr Patten received a report that water was coming out of the 8820 South sump which sat about 10 metres lower than the 8820 North sump. Mr Patten checked on the 8820 North sump at around 5.30am on the morning of 11 June 2014. He drove in via the North access road. He observed that the sump was completely full and that water was flowing down into it from the 8855 Level. In Mr Patten's experience, the volume of water in the 8820 North sump was unprecedented. He called the fixed plant team and was informed that one of the 8855 Wilson Snyder pumps was not operational and that it could not be fixed immediately as the team was waiting on replacement parts to arrive. As water built up in the 8855 dam, it overflowed into the 8855 sump which drained to the 8820 North sump by the drain hole.
Mr Patten believed that the volume of water flowing to the 8820 North sump would be too much for the installed flygt pump to handle. Water was running down the decline in the 8820 South side of the mine. Mr Patten was concerned about water damaging the top dressing and rendering the roadway unsafe. The roadways in the mine were cut into rock and covered with top dressing to make them even. Water running down the roadways created a potential hazard to truck drivers transporting materials within the mine. Consequently, Mr Patten believed that reducing the water level in the 8820 North sump was a matter of some urgency. He believed that the best way to address the problem was to arrange for the pump on the 8855 Level to be fixed or to stop water being pumped up to the 8855 Level from lower levels in the mine.

[26]

Evidence of Anthony Gaydon

During the course of the day shift, Mr Gaydon was working on the services crew with Craig Yode, when he received a radio call from a truck operator informing him that there was water coming out of the 8820 Level onto the decline. Mr Gaydon travelled to the 8820 Level on the southern side, where he observed water leaking out of the fresh air rise (FAR). A FAR is a brick wall built across an access way that had a fan installed in it. The fan was used to circulate air within the mine.
Mr Gaydon and Mr Yode then travelled to the 8820 North access from where they could see the sump. Mr Gaydon gave evidence that the water was higher than the high water mark shown on photographs taken after the incident. Mr Gaydon gave evidence that the water was only a couple of inches below the power box on the wall of the mine. Mr Gaydon tried to make contact with the electricians via radio but these attempts were initially unsuccessful. Mr Gaydon isolated the power to the 8820 Level by turning off the electricity at the mains. He finally contacted Mr Russell by radio, informing him that the water levels were very high. Mr Russell said that he would attend himself.
Mr Russell attended the 8820 North sump and instructed Mr Gaydon and Mr Yode to keep an eye on the water level. After Mr Russell left, Mr Gaydon and Mr Yode checked the 8790 Level (the level below) and observed that no water was flowing through the drain hole. Mr Gaydon concluded that the drain hole in the 8820 North sump was blocked. In a subsequent conversation over the radio Mr Russell told Mr Gaydon he believed that there was a vent bag over the drain hole with a rock on top of it. Mr Gaydon was unsure why this had occurred and decided to enter the sump to unblock the hole. Mr Gaydon removed his clothing with the exception of his gumboots and underwear and walked into the water. He walked to the approximate location of the drain hole attempting to find it by using his feet. By the time he got to the approximate location of the drain hole the water was over his head. At about this time he realised there was no strainer in the drain hole and panicked because there was a risk he could be sucked into the drain hole. Mr Gaydon exited the water immediately and radioed Mr Russell, telling him "there's no vent bag in there". Mr Russell told Mr Gaydon that the drain hole had been deliberately blocked and to "get the f… out of there". Mr Yode placed a chain and a sign across the front of the 8820 North sump before leaving to attend to other duties.
Mr Gaydon recalled completing a CSAfe for the task of unblocking the 8820 North sump drain hole. He did not complete a JSA in relation to the task. When asked why he entered the sump to try and unblock the drain hole before using a pump to reduce the volume of water, Mr Gaydon said that he panicked when he saw the volume of water. He was concerned for the men working on the levels underneath as he believed the water was capable of causing a collapse of the level. Mr Gaydon gave evidence that he entered the sump on foot rather than using an ITC as the ITC was being used for other work and it could not be driven into water over 1 metre deep as the water would likely cause significant damage. Mr Gaydon and Mr Yode left the area and did not go back there during the course of the day shift on 11 June 2014.
At the completion of the day shift Mr Gaydon attended the cross-shift meeting on the surface where he spoke to Mr Hern, Gavin Booth and Andrew Dobbs who had been assigned to undertake the work to be done by the services crew on the 11 June 2014 night shift plan. Mr Gaydon gave evidence that the three night shift workers were laughing at him and recalled Mr Hern calling him 'swamp donkey' and 'little Buddha'. 'Buddha' was the nick name commonly given to Mr Roberts. Mr Gaydon told Messrs Hern, Booth and Dobbs that he had been in the 8820 North sump and that the drain hole was blocked and there was no strainer in it. Mr Hern said to Mr Gaydon words to the effect of 'you are fucking off your head', 'fancy swimming around in that stinking dirty water' and 'well I can guarantee you I won't be in there'. Mr Gaydon replied with words to the effect of 'youse have got the last fucking laugh because youse are the ones that are going to have to unblock it, not me'. Mr Gaydon stated that these comments occurred in the context of a light-hearted exchange.
I found Mr Gaydon to be a witness whose evidence was overstated and given in a slightly dramatic fashion. I do not accept that the water level, when he observed it, was above the high water marks on the walls depicted in the photographs taken after the incident. That evidence, in my view, cannot be reconciled with common sense, and is contrary to the evidence of Mr Chaplain, which I prefer. I accept his explanation as to why he entered the water and that explanation fits with my impression of him that he tended to overreact to situations. I am not satisfied that I should accept his evidence about his radio communications with Mr Russell, where he suggested Mr Russell did not know that the drain hole had been deliberately blocked for the reasons that follow. First, the fact that the drain hole was blocked was noted on the foreman's daily shift plan and Mr Russell had a copy of that. Second, the direction that the 8820 North sump was to be left blocked until further notice was written prominently on the PLOD sheet and Mr Russell and Mr Gaydon both had a copy of that. Third, Mr Yode was not called to give evidence. Fourth, this issue was not canvassed with Mr Russell in evidence, but I note that his memory of the events was poor. Fifth, Mr Gaydon had reason to give that evidence and paint his conduct in a better light. Mr Gaydon had been the subject of disciplinary action for entering the sump as part of the investigation by the defendant into the incident. It was in Mr Gaydon's interests to maintain the same version of events that he provided to the defendant in those disciplinary proceedings. I note that his evidence was incomplete in some regards, and for the reasons that I will come to, I am satisfied that he told Mr Hern at the cross-shift meeting that the drain hole had been blocked with blast bags.

[28]

Evidence of Tony Chaplain

Mr Chaplain gave evidence that around 10am on the day shift of 11 June 2014 Mr Russell radioed him to inform him that the water level on the 8820 North sump was increasing and that the water might run down towards the fan starters. Fan starters were electrical boxes mounted on the walls of the mine which were used to power 90kW fans of ventilation to occupied areas of the mine.
Mr Chaplain made radio contact with Ian Strange, an electrician and informed him to isolate the fan and told him that it was a priority job as a result of the hazard posed by the water potentially coming into contact with the electrical equipment.
Mr Chaplain then met with Mr Russell in the 8980 Level supervisor's office. Mr Russell told Mr Chaplain that the fan starters had been isolated. Mr Russell and Mr Chaplain were concerned that the water might overflow from the 8820 North sump into the FAR.
Mr Chaplain and Mr Russell visited the 8820 North sump at around 2pm. The water from the sump had begun to reach the high point on the 8820 Level. By this time the flygt pump that had been installed in the 8820 North sump was fully submerged. Both Mr Russell and Mr Chaplain gave evidence that the water level had not yet reached the high water marks on the walls depicted in the photographs taken after the incident.
Mr Chaplain resolved to liaise with the oncoming night shift foreman regarding the water level at the 8820 North sump as there was not enough time to formulate a plan to deal with the issue during the day shift. He was concerned that making a major change to the conditions at the 8820 North sump without informing the underground workers may present hazards. He returned to the surface at around 4pm where he began formulating a plan to address the overflowing 8820 North sump. Plans remained in a state of flux, as the fixed plant maintenance team was still working on fixing the 8855 Wilson Snyder pump. Mr Chaplain believed that the best option was to pump water out of the 8820 North sump before attempting to unblock it. He was also hopeful that the Wilson Snyder pump at the 8855 Level would be fixed, within a short time.
Mr Chaplain discussed the situation with Mr Cownie, the oncoming night foreman and Mr McMillan, the oncoming night shift supervisor. They discussed the 8855 pumps and the need to block off the 8890 drain hole and reduce the volume of water in the 8820 North sump before unblocking it. They agreed that the best option would be for the water to be pumped out of the 8820 North sump and down the decline, if necessary. Mr McMillan suggested that James Hern and Gavin Booth might be tasked with unblocking the 8820 North sump drain hole. Mr Chaplain gave evidence that he and Mr Cownie were both adamant that no operator would enter the area until Mr Cownie and Mr McMillan had liaised with them and put together a plan.
Mr Chaplain was a careful and considered witness. His evidence demonstrated the extent of his considerable knowledge of the mine and its processes. I am satisfied that he was doing his best to give honest evidence and that his evidence should be accepted.

[29]

Evidence of Terry Roberts

On the day shift of 11 June 2014 Mr Roberts worked with Jamie Baber on the 9 Level. At around 2pm Mr Roberts and Mr Baber were in the electrician's crib room when they had a conversation with a contract electrician. He told them he had seen a man "swimming" in the sump earlier that day and that the man had been looking for a drain hole. Mr Roberts said words to the effect of "I hope the fuck you don't find it. If he's anywhere within 8 feet he'll get sucked in it".
Mr Roberts was told that the level of the water in the sump was so high that it was in danger of reaching the fan starters, requiring the electricity to be turned off. In Mr Roberts' experience it was unusual for such a large amount of water to be present in the sump. He had only seen this occur on one occasion about four years prior to the incident when he was asked to unblock a sump by the shift supervisor.
Throughout the rest of the day shift Mr Roberts spoke to Mr Baber on a number of occasions about the 8820 North sump drain hole. He warned Mr Baber not to enter the sump should he be given the task of unblocking the drain hole and explained to him that the most effective way to clear the blockage would be to do so from underneath using explosives.
At completion of the day shift around 7pm, Mr Roberts and Mr Baber waited for the night shift workers to arrive. Mr Roberts was concerned that someone would be assigned to unblock the 8820 North sump drain hole. Mr Roberts intended to instruct the night shift workers on how to undertake the task but was told by Mr Cownie that it would not be a problem as no other workers would be unblocking the drain hole.
Mr Roberts was an impressive witness. Whilst he sometimes gave evidence in a colloquial and slightly jovial manner, he was entirely genuine in doing so. I am satisfied that Mr Roberts was an honest witness and that his evidence reflected his considerable experience at the mine and that it should be accepted, with the exception I have set out in [217] below. I am satisfied that Mr Roberts was unfairly treated in the EPB Procedure that was part of the investigation into the incident because the defendant relied on the untested evidence of Mr Gaydon and perhaps others about his previous observations of Mr Roberts' work underground. It was to Mr Robert's credit that his evidence was not tainted by that unfair treatment.

[32]

Evidence of Robert Cownie

At the foreman's shift handover meeting in the foreman's office, Mr Chaplain, Mr Cownie and Mr Howard were present prior to the arrival of Mr McMillan. Mr Chaplain mentioned to Mr Cownie and Mr McMillan that the 8820 North sump drain hole needed to be unblocked. Mr Cownie became aware that the water was flowing from the 8820 North sump down the FAR system. Mr Cownie asked Mr Chaplain if he knew how the hole had been blocked and Mr Howard replied that it could have been with a vent bag or a blast bag. Mr Cownie told Mr McMillan that they might have to put a pump in the sump to get rid of the water.
Mr Cownie gave evidence that he said to Mr McMillan words to the effect 'when those guys get down to 8820, I want them to give me a call before they strike a blow'. Mr Cownie wanted to see the situation for himself because it involved an unusually large volume of water in the sump. Mr Cownie was unsure whether he said this on the surface during the foreman's shift handover meeting or later in the shift supervisor's office underground. At that time Mr Cownie was unaware which operators would be allocated the task of unblocking the drain hole.
Mr McMillan left to attend the pre-shift meeting while Mr Cownie discussed the weekly schedule with Mr Chaplain. Mr Cownie then drove underground to join Mr McMillan in the supervisor's office at the 8980 Level where he was advised that the workers would not be attending to the task of unblocking the 8820 North sump drain hole for a couple of hours. Mr Cownie mentioned that they might need to divert the water to the 8820 South sump or otherwise pump it down the decline. This discussion occurred at about 9.30pm.
Mr Cownie completed several tasks before he heard Mr Booth asking Mr McMillan over the radio to come down to the 8820 North sump. Mr Cownie radioed Mr McMillan and told him that he would get there as he was closer.
Mr Cownie was a good witness who answered questions in a straight forward manner. I formed the impression that he did his best to give honest evidence.

[33]

Evidence of Kenneth McMillan

After arriving at the mine for the night shift on 11 June 2014 Mr McMillan reviewed the supervisor's shift plan before calling Mr Russell. During this conversation, Mr McMillan assigned the task to the operators on his crew, adding the names to the PLOD sheet on a preliminary basis. He then joined Mr Chaplain and Mr Cownie in the foreman's office. During their discussions Mr Chaplain and/or Mr Cownie said that the water level in the 8820 North sump was flowing down the FAR. At the time of the meeting, Mr McMillan understood that the task of unblocking the drain hole was somewhat urgent but there were other jobs to do first. Mr McMillan recalled that neither foreman knew how the drain hole had been blocked. He believed he may have said that he wanted to go down to assess the situation himself to figure out the best way to complete the task.
Following the handover with Mr Chaplain and Mr Cownie, Mr McMillan left to conduct the pre-shift meeting. In relation to the task of unblocking the 8820 North sump he said words to the effect of 'whoever gets there first calls and I'll go down there and we will work out a plan of attack for it'. Mr McMillan directed these words to the two service crews comprising Mr Hern and Mr Booth in one crew and Mr Walkinshaw and Mr Dobbs in the other crew. Mr McMillan did not specifically allocate the task of unblocking the drain hole to either crew as he intended it to be completed by whichever service crew arrived first. Mr McMillan did not direct the workers on how to unblock the drain hole because he believed it had been blocked with ANFO bags chained to the mine wall which would have allowed the blockage to be removed by pulling the chain with an ITC. Mr McMillan was unsure whether Mr Hern or Mr Booth had any experience in unblocking drain holes that had been deliberately blocked.
I have dealt with the issue of the instructions given by Mr McMillan at the pre-shift meeting at [227] to [239] below.
Once underground, Mr McMillan went to the 8980 Level supervisor's office. He was later called to where the remote control booth was being set up for loaders, a job he had allocated some priority to. When he arrived at that location, he was informed that the workers were concerned the roof and walls of the mine were not properly supported and may collapse. He agreed with the workers' assessment and stayed to oversee the necessary remedial measures.
Mr McMillan then drove up to the 11 Level to have the air conditioning in his light vehicle re-gassed. The conditions in the mine were very hot and humid and the air conditioning in Mr McMillan's vehicle was not working. While he was at the workshop he received a communication from Mr Booth asking him to come down to the 8820 North sump straight away as Mr Hern was missing. Mr McMillan drove down to the 8820 North Level and radioed Mr Walkinshaw who confirmed that he was on his way to the sump. Mr McMillan also initiated the emergency protocols within the mine.
I accept that Mr McMillan was a witness who was doing his best to give honest evidence. He became slightly confused in his evidence about the difference between giving an instruction and having the belief that he had given the instruction. This is a common trap for lay witnesses. I accept Mr McMillan's evidence that he had a special interest in safety because his father died whilst working at the mine, many years ago. Mr McMillan had a very clear recollection of the events at the sump in the aftermath of the incident, which is a recognised feature in studies of eyewitness memory. In my view, these recollections were retained by Mr McMillan at the expense of earlier events on which he was not so sure. Overall, I found Mr McMillan to be doing his best to give honest evidence and that his evidence should be accepted.

[34]

Evidence of Gavin Booth

Mr Booth did not recall Mr McMillan giving any instructions in relation to the task of unblocking the 8820 North sump at the pre-shift meeting on 11 June 2014. At the cross-shift meeting, Mr Booth overheard Mr Gaydon talking to Mr Hern but he was not directly involved in the conversation and could not recall anything that was said.
At the start of the night shift Mr Booth and Mr Hern collected a 20kW flygt pump from the 11 Level store which was to be installed in the 8790 sump. They also retrieved two scaling bars and some rope for the task of unblocking the 8820 North sump drain hole.
At around 8pm, Mr Booth and Mr Hern went to the crib room at the 8980 Level and took a 15 minute coffee break. They then proceeded to the 8790 Level to install the flygt pump. They completed this job using an ITC and were assisted by Mr Dobbs. Mr Booth and Mr Hern worked from the basket while Mr Dobbs drove the ITC. Mr Booth understood that the purpose of this task was to allow the water to be pumped out of the 8790 Level once the 8820 North sump had been unblocked. Mr Booth recalled that the 8790 drain hole was blocked but was unsure whether this occurred prior to or during the work on that level. Messrs Booth, Hern and Dobbs worked on the 8790 Level for approximately two hours.
Around 10.30pm, Mr Booth and Mr Hern travelled to the 8820 North sump in the ITC and a light vehicle respectively. Mr Booth did not recall whether he saw a chain and sign hanging from the sump when they arrived. Mr Booth retrieved one or both of the scaling bars and the rope from the light vehicle, whilst Mr Hern put on his harness. They discussed using the scaling bars to "pop the balloon". Mr Booth recalled completing a CSAfe for this task although it could not be located after the incident.
Mr Booth described there being 'heaps of water' in the sump. He and Mr Hern did not complete a JSA because Mr Booth believed the task to be a 'normal, easy job'.
Mr Hern entered the basket and Mr Booth drove the ITC out to the drain hole. Mr Booth stopped the ITC close to the wall of the mine, adjacent to the drain hole, which he believed was about 500mm from the drain hole. The only lighting in the area came from the lights on the ITC and Mr Hern's cap lamp. Mr Booth gave evidence that the water level was about halfway up the wheels of the ITC. Mr Booth then waited with the engine of the ITC running while Mr Hern worked from the basket. Mr Booth saw Mr Hern attempting to use the scaling bar to find the drain hole. Mr Hern had tied the scaling bar to the rope and was trying to spear the scaling bar into the drain hole, whilst standing in the basket. After about 5 minutes, Mr Hern told Mr Booth that he had lost the scaling bar. Mr Booth then reversed the ITC out of the water.
Following this, Mr Booth and Mr Hern travelled to the 8790 North sump in the light vehicle to see if water was draining through the drain hole to the level below. There was no water coming out and Mr Booth concluded that the drain hole was still 'well and truly blocked'.
Mr Booth and Mr Hern then drove back up to the 8820 Level in the light vehicle. Mr Hern told Mr Booth that he needed to retrieve the scaling bar that he had dropped in the water. Mr Booth could not recall the content of the discussion between himself and Mr Hern at this time, but his understanding was that Mr Hern wanted him to drive the ITC back into the water and that Mr Hern was going to use the other scaling bar to find the drain hole and pop the balloon.
When they got back to the ITC, Mr Hern removed his harness and most of his clothing. Mr Booth placed Mr Hern's clothes in the back seat of the light vehicle. At this time, Mr Hern was wearing his underpants, boots and hard hat. Mr Booth told Mr Hern on multiple occasions to put his harness back on, to which Mr Hern replied in words to the effect, 'it'll be right'.
Mr Hern then got into the basket and Mr Booth drove the ITC into the water adjacent to the drain hole to approximately the same location. The basket was lifted just above the height of the water. Mr Hern told Mr Booth to turn off the engine of the ITC and Mr Booth did so.
Mr Hern then climbed out over the front rail of the ITC basket and entered the water. Mr Booth did not see Mr Hern take anything with him at that time. Mr Booth's vision of Mr Hern was partially obstructed by the hydraulics of the ITC. Mr Booth called out to Mr Hern to see if he was 'all good' about 15 seconds after he left the basket. Mr Hern responded that he was 'okay'. Mr Booth noticed that the area went quiet. When he called out to Mr Hern again he got no response. About 15 seconds later he saw a hard hat floating in the water.
Mr Booth called Mr McMillan over the radio and told him that Mr Hern was missing in the sump and that he needed him to come straight away. Mr McMillan put out an emergency call over the radio. The first responders were Susie Hardwick, Mr Dobbs and Mr Walkinshaw. Mr Booth explained that Mr Hern was missing in the sump and the three workers entered the water to search with him. Two contractors from Pybar Mining Services arrived shortly afterwards.
The workers located Mr Hern in the sump submerged under the water. They saw that one of his legs was in the drain hole up to about thigh level. The workers submerged themselves and tried to lift Mr Hern out of the drain hole but could not do so. The workers then placed a harness on Mr Hern and attached the lanyard to the basket of the ITC. On the first attempt to lift Mr Hern out of the sump the lanyard broke. The harness that Mr Hern was wearing was then attached to the ITC with a tow rope. The hydraulic system on the ITC was then used to extract Mr Hern from the drain hole.
After the incident, Mr Booth was taken by Mr McMillan to the 8820 refuge chamber because he was distressed. At that time, in accordance with the mine's emergency response protocols, Mr Booth was asked to compile a handwritten statement. In that statement, Mr Booth stated that 'the scaling bar got stuck down the drain hole'. He also stated, '[S]o James and I went back to 8820 Nth and he said to me I've got to go in and get it out or I will get in trouble, I said don't worry about it we will get another one and he said no'.
Mr Booth was at times distressed in the course of giving evidence. It was apparent that the incident has had a deep and long-lasting psychological effect on him. Mr Booth presented with a very flat affect. His recollection of the events was generally poor. Despite what may appear from the transcript as a lack of co-operation to recall a significant number of matters, in my view Mr Booth was doing his best to assist the Court and to give honest evidence.

[35]

Findings of fact relating to the incident

After the unsuccessful first attempt, I infer that Mr Hern wanted to travel to the level below to see if any water was coming out of the drain hole, to determine if it was safe to go into the water to recover the scaling bar. I infer that he was concerned about the suction force of the water that would be caused when the drain hole was unblocked and that he wanted to make sure that the blockage had not been compromised before entering the water.
I find that the water depth at the drain hole was about chest height on Mr Hern when he was standing in the vicinity of the drain hole.
I find that the drain hole became unblocked suddenly as a result of an action of Mr Hern when he was in the water for the following reasons. In my view, the scaling bar would not have been sucked down the drain hole (see [164] below) if it had been lying flat on the ground adjacent to the drain hole, because of its shape and weight. Based on the fact that the scaling bar went down the drain hole, I infer that it was in a vertical position at the time when the drain hole became unblocked. I infer that the scaling bar was in the vertical position because when Mr Hern lost the scaling bar in the water it become stuck down the drain hole and was in an upright position and when he found it in the water, his retrieval of it caused the drain hole to become unblocked, or he used the scaling bar to burst the blast bag while he was standing next to the hole.
The pressure of the water caused his leg to become sucked into the drain hole to about his thigh because Mr Hern was in close proximity to the drain hole when it was suddenly unblocked.
The water pressure was so great that Mr Hern could not free himself. The head pressure of the water was substantial because the incident occurred more than 1000m below the surface.
Mr Hern became trapped under the water which was now over his head because his leg had been sucked down the drain hole.
The water pressure was so great that Mr Hern could not be freed without mechanical assistance.

[40]

The Sump Procedure

On or about 17 February 2015, the defendant published a document entitled "Management of Underground Sumps" (the Sump Procedure). The purpose of the Sump Procedure was to provide instruction in the safe work practices regarding the management and maintenance of underground sumps. The Sump Procedure required workers to reduce the volume of water in a sump before working in, around and under sumps. It warned that a drain hole was about 200mm in diameter and required that the strainer must remain in the hole at all times when there is water around and personnel are on the ground nearby. Where possible, the Sump Procedure provided a pump should be installed to reduce the water before attempting to unblock drain holes with high water. If the strainer was required to be removed with water surrounding it, personnel must operate from an ITC basket with fall arrest and the area cordoned off with an "Authorised Persons Only" sign.
The Sump Procedure provided that personnel could clear around drain holes where the water level was not above gumboot height and the level of mud was not above half gumboot height. Where practical, the Sump Procedure required mud to be cleared away to reduce the chance of injury. The Sump Procedure warned that if the level of water or mud could not easily be determined then it should be treated by workers as high water. Where a drain hole was fully submerged or water/mud was above the allowed levels, attempts had to be made to lower the water level before attempting to clear the drain hole. If this was unsuccessful then a separate risk assessment had to be carried out before attempting to clear the drain hole. The Sump Procedure mandated that under no circumstances were personnel allowed to enter high water to unblock the drain hole.
The Sump Procedure provided that when unblocking drain holes, a specific risk assessment had to be carried out, giving consideration to the safety of the personnel performing the task as well as the management of the water at the lower level when the drain hole was unblocked. Where possible, a drain hole should be unblocked from below using a drill rig. Before blocking drain holes the Sump Procedure required a risk assessment to be carried out to determine how the hole would be unblocked and the water managed during the time that it was blocked.
The Sump Procedure also provided procedures for installing pumps, retrieving pumps, cleaning pumps and bogging sumps, which are not particularly relevant to this judgment.
The Sump Procedure was developed by Mr Wilson and a team of people from different areas of the mine, with input from the HSET. The workers were trained on the requirements of the Sump Procedure when it was introduced.

[42]

The relevant law

The offence is one of strict liability: section 12A of the Act.
A person is a "worker" if the person carries out work in any capacity for a person conducting a business or undertaking, including work as an employee, a contractor or subcontractor or an employee of a contractor or subcontractor: section 7 of the Act.
The content of the duty is set out in section 19 of the Act, which relevantly provides: (1) A person conducting a business or undertaking must ensure, so far as is reasonably practicable, the health and safety of: (a) workers engaged, or caused to be engaged by the person, and (b) workers whose activities in carrying out work are influenced or directed by the person, while the workers are at work in the business or undertaking. … (3) Without limiting subsections (1) and (2), a person conducting a business or undertaking must ensure, so far as is reasonably practicable: (a) the provision and maintenance of a work environment without risks to health and safety, and (b) the provision of safe plant and structures, and (c) the provision and maintenance of safe systems of work, and (d) the safe use, handling and storage of plant, structures and substances, and … (f) the provision of any information, training, instruction or supervision that is necessary to protect all persons from risks to their health and safety arising from work carried out as part of the conduct of the business or undertaking, and (g) that the health of workers and the conditions at the workplace are monitored for the purpose of preventing illness or injury of workers arising from the conduct of the business or undertaking.
The inclusive list of specific obligations set out in section 19(3) of the Act have each been identified at common law.
The requirement to 'ensure' means to guarantee or make certain: Carrington Slipways Pty Ltd v Callaghan (1985) 11 IR 467 at 470.
Safety cannot be ensured if a risk to the health and safety of a worker exists. The existence of the risk constitutes a breach of section 19 of the Act. It is not necessary that there is an accident or that a person is injured: Kirk v Industrial Court of New South Wales (2010) 239 CLR 531 at [13]. The relevant risk for the commission of the section 32 offence is the risk of death or serious injury.
The word "risk" is not defined in the Act. Risk means the mere possibility of danger and not necessarily actual danger: R v Board of Trustees of the Science Museum [1993] 1 WLR 1171 and Thiess Pty Ltd v Industrial Court of New South Wales (2010) 78 NSWLR 94 at [67].
An incident causing injury may be evidence of the presence of a risk and may be relevant to sentencing as a measure of the severity of the harm suffered as a result of the risk. But a distinction must be drawn between the specific risk that manifested in the incident and the general class of risk that the analysis must focus on. Paying too close attention to the specific risk resulting in an incident can lead to error: Tangerine Confectionery Ltd and Veolia ES (UK) Ltd v R [2011] EWCA Crim 2015 and Director of Public Prosecutions v Vibro-Pile (Aust) Pty Ltd (2016) 49 VR 676 at [3]-[6].
A duty imposed to ensure health and safety requires the person to eliminate risks to health and safety so far as that is reasonably practicable, and if that cannot be done, to minimise those risks so far as is reasonably practicable: section 17 of the Act. The risk should be identified with sufficient precision to determine if it was reasonably practicable to eliminate it or minimise it.
"Reasonably practicable" is defined in section 18 of the Act. The Court must take into account and weigh up all relevant matters including; 1. the likelihood of the risk concerned occurring, and 2. the degree of harm that might result from the risk, and 3. what the defendant knows or ought reasonably to know about; 1. the risk, and 2. ways of eliminating or minimising the risk, and 1. the availability and suitability of ways to eliminate or minimise the risk, and 2. after assessing the extent of the risk and the available ways of eliminating or minimising the risk, the cost associated with either of those options, including whether the cost is grossly disproportionate to the risk.
The state of knowledge applied to the definition of practicable is objective. It is that possessed by persons generally who are engaged in the relevant field of activity, and should not be assessed by reference to the actual knowledge of a specific defendant in particular circumstances: Laing O'Rourke (BMC) Pty Ltd v Kirwin [2011] WASCA 117 at [33].
The reasonably practicable requirement applies to matters which are within the power of the defendant to control, supervise and manage: Slivak v Lurgi (Aust) Pty Ltd (2001) 205 CLR 304 at [37] per Gleeson CJ, Gummow and Hayne JJ.
The phrase "exposed to risks" contained in section 8(2) Occupational Health and Safety Act 2000 was interpreted to mean that a person was sufficiently proximate to the source of a risk for the risk to come home, irrespective of the mechanism by which that could happen: Thiess.
The section 19 duty requires knowledge of the risk emanating from the activities of the defendant: Slivak. Foreseeability of the risk to persons from the activity is an element of this question of knowledge. It would not generally be practicable to take measures to guard against a risk to safety that was not reasonably foreseeable: Genner Constructions Pty Ltd v WorkCover Authority of New South Wales [2001] NSWIRComm 267 at [68].
The statutory duty is not limited to simply preventing foreseeable risks of injury. The duty is to protect against all risks, if that is reasonably practicable. Reasonably practicable means something narrower than physically possible or feasible: Slivak at [53] per Gaudron J.
The words "reasonably practicable" indicate that the duty does not require a duty holder to take every possible step that could be taken. The steps to be taken in performance of the duty are those that are reasonably practicable for the duty holder to achieve the provision of and maintenance of a safe working environment. Bare demonstration that a step might have had some effect on the safety of a working environment does not, without more, demonstrate a breach of the duty: Baiada Poultry Pty Ltd v R (2012) 246 CLR 92 at [15], [33] and [38] per French CJ, Gummow, Hayne and Crennan JJ.
A duty holder must have a proactive approach to safety issues. The question is not did the duty holder envisage a particular danger, but rather should it have: WorkCover Authority of New South Wales v Kellogg (Aust) Pty Ltd [1999] NSWIRComm 453.
A duty holder must have a structured and systematic approach to risk management: WorkCover Authority of NSW v Atco Controls Pty Ltd (1998) 82 IR 80 at 85 per Hill J and Inspector Ching v Bros Bins Systems Pty Ltd [2004] NSWIRComm 197 at [32].
A duty holder must have regard not only for the ideal worker but also for one who is careless, inattentive or inadvertent: Dunlop Rubber Australia Ltd v Buckley (1952) 87 CLR 313 at 320 per Dixon CJ. If there is a foreseeable risk of injury arising from a worker's negligence in carrying out his or her duties then this is a factor which the duty holder must take into account: Smith v Broken Hill Pty Ltd (1957) 97 CLR 337 at 343. It may not always be possible to foresee various acts of inadvertence by workers but duty holders must conduct operations on the basis that such acts will occur and they must be guarded against to the fullest extent practicable.
The unforeseeable behaviour of a disobedient worker may well lead to the happening of an event that could not be reasonably foreseen and therefore was not reasonably practical to guard against: WorkCover Authority of New South Wales v Kirk Group Holdings Pty Ltd (2004) 135 IR 166 at [129].
One of the matters PCBUs must recognise and plan for is the inevitability of human error ranging from inadvertence, inattention or haste through to foolish disregard of personal safety and deliberate non-compliance with safe systems of work: R v Commercial Industrial Construction Group Pty Ltd (2006) 14 VR 321 at [49] and Director of Public Prosecutions v JCS Fabrications Pty Ltd and JMAL Group Pty Ltd [2019] VSCA 50 at [51].
Where an employer is found to have laid down a safe and proper practice and there is no evidence that the employer failed to use due diligence to see that the practice is observed, then a casual failure by inferior employees, even if of supervisory rank, to observe that practice on a particular occasion will not render the employer criminally liable for a failure to ensure safety: Collins v State Rail Authority of New South Wales (1986) 5 NSWLR 209 at 215E.
The question of what is reasonably practicable is also a question of fact, depending on the circumstances of each case. The fact that an employee has carried out work carelessly or omitted to take a precaution does not preclude the employer from establishing that everything that was reasonably practicable in the employer's undertaking to ensure that persons were not exposed to risks to their health and safety had been done: R v Nelson Group Services (Maintenance) Ltd [1998] 4 All ER 332 at 351e-f.
The relevant question on causation is whether the act or omission of the defendant was a significant or substantial cause of the worker being exposed to the risk of injury: Bulga Underground Operations v Nash [2016] NSWCCA 37 at [127].
The question is to be determined by the application of common sense to the facts, bearing in mind that the purpose of the inquiry is to attribute legal responsibility in a criminal matter: Royall v The Queen (1991) 172 CLR 378.
Regard must be had to the scope and objects of the Act: Simpson Design and Associates Pty Ltd v Industrial Court of New South Wales [2011] NSWCA 316 at [79]-[102]. The relevant question is not whether the particularised failures of the defendant were the cause of the injury to the worker, but rather whether there was a causal relationship between the act or omission and the risk to which the worker was exposed: Bulga Underground at [130].

[49]

Was the pleaded risk reasonably foreseeable?

The prosecution submitted that it was reasonably foreseeable that Mr Hern may enter the water in the course of unblocking the drain hole for a number of reasons. Namely, Mr Hern was not prohibited from doing so, he was given incomplete instructions on matters relevant to the task including how to do it, Mr Roberts regularly entered high levels of water in the mine and Mr Gaydon entered the sump on the day of the incident.
I am not satisfied that the pleaded risk was reasonably foreseeable for the reasons that follow.
Much of the prosecution case was based on the lack of planning or the need for a risk assessment of the task of unblocking the drain hole. The prosecution submitted that as a result, Mr Hern did not have the information, training and instruction he needed to perform the task. Contrary to that submission, I am satisfied that at the time of his first attempt to unblock the drain hole, he knew that the drain hole had been blocked with blast bags and that the blockage could be removed by bursting the blast bags with a sharp implement. He knew the approximate location of the drain hole, because it was marked on the wall in orange paint. He knew the depth of the water from his discussion at the cross-shift meeting with Mr Gaydon or alternatively by his use of the scaling bar. He knew that the sudden unblocking of the drain hole was likely to cause the water to drain quickly with considerable suction force. I am satisfied that the state of Mr Hern's knowledge at the time of his first attempt: 1. was sufficient for him to undertake the task safely; 2. was derived from the operation of the defendant's safety system; 3. was demonstrated by his first attempt to unblock the drain hole; and 4. required him to complete a JSA and to involve Mr McMillan in planning to undertake the task safely before undertaking any work.
For the reasons already given, it was not necessary for Mr Hern to enter the water to unblock the drain hole. Mr Hern had been trained on the WiB Procedure and applied that training, removing any danger to himself and Mr Booth in his first attempt.
The workers, including Mr Hern, knew that unblocking the drain hole whilst in the water was dangerous because it carried with it the risk that a body part could become trapped in the drain hole by reason of the water pressure. Mr Roberts gave evidence that he would not approach a drain hole without a strainer in it because of the risk of having a body part sucked into the drain hole. Mr Roberts expressed this concern to Mr Baber when he found out that Mr Gaydon had been in the 8820 North sump during the day shift on 11 June 2014. Mr Hern was present with Mr Walkinshaw when they forcibly removed a broken strainer in a sump with a loader about a week before the incident. Mr Walkinshaw described the water draining quickly and with considerable suction producing a loud noise. Mr Gaydon was aware of that risk and became quite concerned for his safety, when he entered the 8820 North sump during the day shift on 11 June 2014 to determine why it was flooded and realised there was no strainer in the drain hole. Further, on 11 June 2014, Mr Hern and Mr Booth travelled to the 8790 Level after their unsuccessful first attempt to see if any water was draining out of the drain hole, which I am satisfied Mr Hern wanted to do to determine if it was safe to go into the water and retrieve the scaling bar.
I accept the evidence of Mr Roberts about his work in and around sumps and prefer it to the evidence given by others, particularly Mr Gaydon, about his work. From about 2006, Mr Roberts' primary role at the mine was as a backfill technician. He also on occasions unblocked drain holes and cleared around strainers on a daily basis during the course of completing his other duties. Clearing around strainers first became an issue when the mine started to use the plastic fibres in the shotcrete. Mr Roberts gave evidence that in 'a few' sumps that were dug out later, that the drain hole was in a deeper part of the sump, rather than close to the edge. From the evidence, I do not know how many such sumps there were. Mr Roberts gave evidence that he would organise his work in such a way that he would not get wet when working at the bottom of drain holes and when he was generally working around water. I infer from his evidence that he did so to maintain his comfort during a shift. Mr Roberts gave evidence that he was 'short' and estimated that he was 5'7" or 5'8" in height. To my observation he was probably shorter than that estimate by a few inches. Mr Roberts gave evidence that he wore the waders to prevent getting water in his gumboots, thereby making him uncomfortable. This was understandable given his relatively short stature. I infer from his evidence that Mr Roberts put on the waders if he thought that it was possible that the water could be at or around the height of his gumboots, rather than only donning them in response to the actual height of the water. I am satisfied that for a considerable proportion of the times that Mr Roberts worked in waders, that he worked in water that was not above gumboot height. Mr Roberts gave evidence that he would not approach a drain hole unless he could see the strainer, which would have been no more than 800mm above the drain hole. Mr Roberts gave evidence that the deepest water that he entered on foot would be to the level of his hip, which is consistent with the height of the strainer when placed in a drain hole.
Mr Roberts estimated that he had entered water of that depth about once or twice per month. In my view, this should be treated as no more than a general estimate and I do not accept it as accurate. Mr Roberts was asked a lot of questions about a very small part of his work. I am satisfied that this focussed his mind on the topic and that this produced an overestimation of the true position. I accept that Mr Roberts did not use the waders to submerge himself indiscriminately in large bodies of water in the mine.
Mr Gaydon gave evidence that he entered water on one occasion that was waist deep, but that he could not recall the circumstances of that. I do not accept his evidence on this point for the reasons I have set out at [106] above.
The evidence was that no other worker, besides Mr Roberts, went into the water to clear strainers when the water was above gumboot height. When the water was above gumboot height the workers cleared strainers from the basket of an ITC, in accordance with the WiB Procedure.
There was no evidence that the supervisors or foremen on duty during the day shift on 11 June 2014 knew Mr Gaydon had gone 'swimming' in the sump. Mr Gaydon was not instructed to enter the sump to unblock it. He entered the sump because he was acting under a mistaken belief that the presence of the water posed a risk of the mine collapsing. He 'panicked' in response to what he believed was a major safety threat in the mine. On the evidence, he clearly overreacted to the situation as a result of his inexperience. Whilst it is clear that the incoming crew at the cross-shift meeting had heard about his conduct in the previous shift, the evidence did not reveal how they knew. There is simply no evidence on this point, and I am not permitted to speculate on how the workers heard about Mr Gaydon's activities or who else might have known.
The water in a sump was particularly dirty and unpleasant. Sumps were often used by the workers as a urinal if they were working on a level away from toilet facilities. This was a view expressed by Mr Hern to Mr Gaydon at the cross-shift meeting on 11 June 2014, to the extent that Mr Hern told Mr Gaydon he would not be getting into the water.
The workers were required to wear Personal Protective Equipment (PPE) at all times. The required PPE consisted of a long-sleeved shirt, long trousers, hard hat, safety glasses, safety boots (including gumboots), underground belt and self-rescuer. A self-rescuer was a portable re-breathing system that allowed its wearer to recycle exhaled air. The removal of these items whilst underground was forbidden unless in a crib room or the toilet, where PPE could be taken off. A failure to wear PPE was a matter for which workers could be and were disciplined. Mr Hern's removal of his clothing was a significant breach of the defendant's safety system.
Mr Hern was required to apply the CSA Controls and to complete a CSAfe. Mr Booth gave evidence that he believed he completed a CSAfe for the task of unblocking the drain hole. It could not be located after the incident. Ms Gilbert gave evidence that the collection of completed CSAfe forms was not always achieved for a variety of reasons including, that they were inadvertently taken home by the worker or that in the aftermath of an incident they were not turned in. The evidence from all of the workers was that the CSAfes were completed because the supervisors and the foremen would undertake spot checks to ensure they were done. If Mr Hern was contemplating entering the water and he completed a CSAfe, bearing in mind the CSA Controls, it is likely that he would have identified that he could not control the risk presented by the large volume of water and that would have prompted him to prepare a JSA, or at the very least contact Mr McMillan.
The workers had all been trained on the JSA Procedure. The task of unblocking the drain hole when there was a large amount of water present, required the completion of a JSA, which would have necessitated the involvement of the supervisors.
Whilst it was 'within the limits of imagination' to anticipate that a worker may enter the water or fall into it, I am not satisfied that this demonstrates that it was reasonably foreseeable that a worker would do so and thereby be exposed to the pleaded risk. In reality, the workers did not enter water contained in sumps because of the way they were designed. On the rare occasions Mr Roberts entered the water around drain holes, he took adequate precautions. The workers usually entered water above gumboot height in an ITC basket. Based on all the evidence, I am not satisfied that it was reasonably foreseeable that the workers would enter or fall into large volumes of water in the mine where there was a risk of submersion.

[50]

Mr McMillan's instructions at the pre-shift meeting

The evidence raised a factual issue that it is convenient to deal with at this point.
Mr Cownie gave evidence that he instructed Mr McMillan to tell the workers to call him so that he could be present to work out a way of unblocking the drain hole. Mr Cownie wanted to be there because the volume of water present made the task unusual. Mr Cownie could not recall if he gave that direction to Mr McMillan during the foreman's shift handover meeting or when they were underground in the 8980 supervisor's office.
Mr Cownie recalled asking Mr McMillan in the underground supervisor's office when he thought the service crews would get to the task of unblocking the drain hole. Mr McMillan replied that he thought they would be a couple of hours. As a result, Mr Cownie thought that he had time to look at some other areas of the mine before attending to the sump. Mr Cownie said to Mr McMillan that if there was a lot of water present it could be pumped down to the next level or alternatively down the decline.
Mr McMillan gave evidence he understood the water level in the sump was high enough to get over the slight rise in the level and run down into the FAR system based on his discussions with Mr Cownie and Mr Chaplain. He believed he said that he wanted to go down and have a look for himself to determine the best way to deal with the water. Mr McMillan's evidence was that he said, 'we need to get the re-entry done first and another job on the list for the night is unblocking the 8820 sump. Whoever gets there first calls and I'll go down there and we'll work out a plan of attack for it'. The reference to re-entry referred to the task of setting up the control huts for the remote loaders.
In a Record of Interview conducted by Inspector Richards with Mr McMillan on 26 June 2014, Mr McMillan was asked about his ("specific instruction") to Mr Hern and Mr Booth at the pre-shift meeting. Mr McMillan relevantly replied, ("that we need to go down and block off the drain hole at 8790 down to 8760. That pump is youse pulled out fellows and the extension cable that got it, we need that put back in because we need to go up and unblock the drain hole at the 8820 north"). As I understand the position, in the Record of Interview, Mr McMillan did not say anything about the workers calling for him to come down to the sump before the work commenced.
Some confusion was introduced into Mr McMillan's evidence by the questions that he was asked in evidence-in-chief. I pause to note that this was entirely inadvertent. He gave direct evidence of the instruction initially. He was then asked if that evidence was evidence of his belief. Mr McMillan thereafter agreed that it was evidence of his belief and that he was uncertain about giving the direction.
I have had access to a short excerpt from the transcript of Mr McMillan's Record of Interview. I have heard that part of the recorded interview played in Court. I do not think that it is fair to Mr McMillan to say that his recollection of the ("specific instruction") was sufficient to cover everything of relevance that was said to the workers at the pre-shift meeting about the unblocking of the drain hole. I also note that in the Record of Interview Mr McMillan told the investigators that he and Mr Cownie were 95% sure at that time that the drain hole had been blocked using a blast bag, which was inconsistent with his evidence.
Mr Walkinshaw gave evidence that Mr McMillan told the service crews at the pre-shift meeting to install a pump at the 8790 Level and to block the drain hole at that level. Mr McMillan instructed them to block the drain hole so that the blockage could be removed by pulling a rope or pulling a chain. Mr McMillan said the drain hole at the 8820 North sump had been blocked with ANFO bags and that there was a rope on the wall to remove the blockage. Mr McMillan directed those words to Mr Hern. Mr Walkinshaw recalled that Mr McMillan gave a series of directions to the service crews about other tasks which took priority over the unblocking of the drain hole. These included, going to another level to extend the ventilation and getting some services ready for a drill rig.
Mr Walkinshaw gave evidence that Mr McMillan instructed that the sump drain hole at the 8790 Level was to be blocked and a pump installed prior to the unblocking of the 8820 North sump drain hole. Mr Walkinshaw gave evidence that once underground he had a further discussion with Mr Hern outside the 8980 crib room. Mr Hern told Mr Walkinshaw that he had been informed by Mr Chaplain at the cross-shift meeting that the drain hole at the 8820 North sump had been blocked with a blast bag, not an ANFO bag. Mr Hern told Mr Walkinshaw he intended to unblock the hole using a scaling bar, by dropping the scaling bar onto the bag and popping it like a balloon. Mr Walkinshaw told Mr Hern that if he could not unblock the drain hole using this method, to contact him and they would contact Mr McMillan to try another method including the use of explosives to blast the blockage from above. In cross-examination, Mr Walkinshaw could not recall Mr McMillan giving him instruction to the effect that he should be called down to the sump before any work was done. As I understood his evidence, he was not in a position to deny that those words were said.
Mr Dobbs gave evidence that at the pre-shift meeting, Mr McMillan told the meeting attendees that the 8820 North sump had been blocked and had to be unblocked. He advised the workers they needed to see their cross-shift counterpart. Mr Dobbs understood those remarks were addressed to Mr Hern and Mr Booth. Mr Dobbs did not recall anything else being said about the 8820 North sump generally, nor how it had been blocked or was to be unblocked. Mr Dobbs gave evidence that he was present during the cross-shift meeting between Mr Hern and Mr Gaydon. Mr Gaydon told them that he found out late in the day shift that the drain hole had been blocked by a blast bag and could be unblocked using something sharp such as a scaling bar to pop the bag. Mr Gaydon said that he had been told the drain hole was blocked with a blast bag by Mr Chaplain. In cross-examination, Mr Dobbs could not recall Mr McMillan giving a direction for the crews to call him to work out a plan of attack. He could not deny that those matters may have been said.
Mr Booth gave evidence that Mr McMillan asked him and Mr Hern at the pre-shift meeting to unblock the 8820 North sump by popping the balloon in the drain hole. Mr Booth could not recall if he had had any further discussions with Mr McMillan during the course of the shift. After refreshing his memory from the Record of Interview conducted on 26 June 2014, Mr Booth could not recall any instructions he was given about unblocking the drain hole. Mr Booth was not part of the cross-shift meeting between Mr Gaydon and Mr Hern. Mr Booth had discussed unblocking the drain hole with Mr Hern and from that discussion understood Mr Hern intended to use a scaling bar to burst the blast bag in the drain hole. Mr Booth could not recall whether Mr McMillan gave the direction to call him before commencing work at the pre-shift meeting.
Susie Hardwick, the water truck driver, did not recall Mr McMillan saying anything about the 8820 North sump task at the pre-shift meeting. Ms Hardwick saw the cross-shift meeting taking place between Mr Hern, Mr Booth, Tony Gilbanks and Mr Gaydon but did not hear what was said. Later in the shift when she was working on the water truck, Ms Hardwick overheard conversations on the radio between Mr Hern, Mr Booth and Mr McMillan. In those communications, Mr Hern or Mr Booth were discussing with Mr McMillan what they were doing and what jobs they had finished. She recalled Mr Hern and Mr Booth were somewhere towards the bottom of the mine fixing a vent bag.
Overall, I am satisfied that Mr McMillan did instruct the workers to call him to the sump before undertaking any work. I accept that this was his intention, following his discussion with Mr Cownie and Mr Chaplain, and that he did communicate this to the workers in the course of the pre-shift meeting.
If I am wrong on this conclusion, this was a casual failure of Mr McMillan at a busy time. It was not information that was critical to the safety of the workers involved, when viewed prospectively, in the circumstances known at that time. In my view, the supervisory staff were concerned about how the large volume of water would be managed when the drain whole was unblocked. This involved a potential safety concern for all the workers in the mine below the 8820 Level, not just the workers tasked with unblocking the drain hole, which is why Mr Cownie wanted to assess the situation for himself.
The JSA Procedure required the workers to prepare a JSA for the task of unblocking the drain hole, which necessitated the involvement of Mr McMillan to assess the situation for himself and approve it. In other words, the JSA Procedure should have been followed, resulting in Mr McMillan being called to the sump before work was undertaken, in the absence of the direction he intended to give at the pre-shift meeting.

[52]

[16] Of the Summons [16] The Defendant failed to ensure, so far as was reasonably practicable, that a safe work environment was provided for undertaking the task of unblocking the 8820 North sump. In particular, the Defendant failed to reduce the depth of the water in the 8820 North sump by pumping water out of the 8820 North sump prior to Mr Hern being required to undertake the task of unblocking the 8820 North sump drain hole.

It is unclear from the pleading how the defendant should have gone about reducing the level of the water in the sump. In combination with [19] of the Amended Summons, the prosecution's case appears to be that Mr McMillan should have directed the service crews to reduce the level of water in the sump by pumping it out before trying to unblock the drain hole.
Reducing the depth of the water in the 8820 North sump was a way of eliminating or minimising the pleaded risk. The consensus of the supervisors, foremen and Mr Howard at the commencement of the night shift on 11 June 2014 was that the water level should have been reduced by pumping water out of the sump before attempting to unblock the drain hole. This would have dealt with the water in a controlled way, avoiding a subsequent hazard, not simply moving the problem to another place in the mine in an uncontrolled way.
This could have been done with the available pumps in the mine. The water could have been pumped to the 8820 South sump or simply down the decline. At the bottom of the decline there were undeveloped parts of the mine that were not being used and if the water ended up there it was unlikely to cause any concern.
The placing of pumps in sumps was a usual task and done often by service crews using an ITC and had been done by Mr Hern and Mr Booth on the night of the incident.
There was no cost to the defendant in reducing the water level in the sump before unblocking the drain hole.
The particular does not specify to what level the water should have been lowered. There are a number of possibilities. First, reducing the water to a level where the drain hole could have been approached on foot, likely a level below gumboot height. This was the level of water specified in the Sump Procedure adopted by the defendant after the incident. Second, reducing the water to a level where the pleaded risk was eliminated. Third, reducing the water to a level where the pleaded risk was minimised.
I cannot ascertain the water levels involved in the second and third options. The risk of drowning as a result of a trapped body part is present in relatively shallow water, including in my view, water that was 'below gumboot height'. It is possible that the level below gumboot height was chosen in the Sump Procedure for the comfort of the workers, to avoid getting water in their gumboots, as opposed to eliminating the pleaded risk.
I do not know how long it may have taken to pump water out of the sump to the appropriate level and if the time involved would have rendered this step impractical. Further, water was still flowing into the sump as a result of the failure of the #2 Wilson Snyder pump at the 8855 pumping station. The video footage taken at the sump the next day by the investigators showed a large volume of water flowing into the sump from the drain hole above it. In my view, this would have had a significant impact on the ability of a pump installed in the sump to reduce the water level to the required height, whatever that was. It may have been necessary to install a series of pumps or a Warman pump to achieve the desired outcome. The size of a Warman pump may have introduced problems of practicality. Having regard to the volume of the water in the sump, the filling of a Warman tank was unlikely to have had much impact on the water level in the sump.
By the time Mr Hern and Mr Booth attended the sump, the power to the level had been isolated to prevent an electrical short. Mr Roberts gave evidence that a 50kW electric pump was the minimum capacity pump required to be effective and that an air pump would not have been effective. He was unsure how it could have been set up when the power to the level had been isolated.
I am not satisfied that it was reasonably practicable for Mr McMillan to have given this direction without assessing the situation for himself, because without doing so the direction was likely to lack content. There were a number of possibilities that were discussed amongst the supervisors on the surface before the commencement of the night shift. The choice between these options was dependent on other factors. For example, pumping a large quantity of the water down the decline was likely to have a significant effect on the quality of the roadway, or alternatively, pumping the water to another location like the 8820 South sump depended on that sump having capacity to receive the water. Whilst both options were possible they were not necessarily reasonably practicable.
For the reasons already given, I am not satisfied that the pleaded risk was reasonably foreseeable.
Taking into account all of the evidence I am not satisfied beyond reasonable doubt that the particular of breach provided for in [16] of the Amended Summons was a reasonably practicable measure.

[54]

The completion of a JSA

The first limb of this particular required the defendant to conduct a JSA for the task of unblocking the drain hole. The particular does not specify how the defendant should have completed a JSA. In combination with [19] of the Amended Summons it was the prosecution's case that Mr McMillan could have directed the service crews at the pre-shift meeting to complete a JSA before unblocking the drain hole.
It was common ground that a JSA should have been prepared because the unblocking of the drain hole was a Non-Standard Job as defined in the JSA Procedure.
The terms of the JSA Procedure required workers to ensure that they conducted JSAs when required by the JSA Procedure and supervisors to ensure that workers conducted JSAs when required to do so by the JSA Procedure.
I am satisfied on the evidence that all of the workers, including Mr Hern and Mr Booth, were trained on the JSA Procedure and understood when a JSA was required to be completed.
Mr Hern and Mr Booth attended the sump and had seen the conditions prior to attempting to unblock the drain hole.
Up and until this point, Mr McMillan had not had the opportunity to look at the conditions at the sump for himself. He had discussed with Mr Cownie attending the location during the course of the shift. I accept that it was his intention to do so, but he had been required elsewhere.
Mr McMillan probably knew enough without attending the sump to realise that a JSA should be done, but in my view stopped short of requiring a JSA until he had assessed the situation for himself. In the circumstances, this was reasonable because without attending the sump he may not have been in a position to understand the necessary matters to prepare or review an effective JSA. He also knew that the service crews had been trained on the JSA Procedure and that there was an obligation on those workers to prepare a JSA if one was required. I am satisfied that if he had attended the sump that he would have required the workers to complete a JSA.
A further question arises as to what the content of a proposed JSA should have been. For the reasons already given, I am satisfied that Mr Hern understood the hazard presented by entering the water and that the correct way to control that hazard was to work from the basket of the ITC in accordance with the WiB Procedure. If Mr Hern had prepared a JSA based on the methodology of his first attempt, it may have been accepted by Mr McMillan as appropriate. Mr McMillan may have required Mr Hern to reduce the water level as a first step because that process had been discussed amongst the supervisory staff. That would not have had any impact on the safety of the methodology adopted in Mr Hern's first attempt, but it may have made the task easier. The content of the proposed JSA is a matter that involves some speculation on the pleaded case.
I am left with doubts about this particular and I am not persuaded that it was reasonably practicable to the criminal standard.

[55]

Implement a Safe Work Procedure

This particular is based on the Sump Procedure introduced and implemented by the defendant on 17 February 2015. The Sump Procedure was formulated by Mr Wilson because the requirements of the MSI adopted on 13 June 2014, requiring the preparation and implementation of a JSA, were too onerous and impractical. Most of the work around sumps did not give rise to safety concerns and the process involved a lot of worker and supervisor time.
On the prosecution case the implementation of a Safe Work Procedure was reasonably practicable because the Sump Procedure was developed and implemented about eight months after the incident. The prosecution submitted that the lack of a formal work procedure for the management of water in underground sumps left the workers to their own devices to improvise ad hoc methods for blocking and unblocking drain holes.
In assessing whether the implementation of the Sump Procedure was reasonably practicable, I must determine that issue prospectively and without the benefit of hindsight. A significant consideration in that analysis is that the Sump Procedure was developed with the knowledge of the specific circumstances of Mr Hern's death.
I am satisfied that the clearing of plastic fibres and rock from around strainers was a routine task at the mine, which was done at times when a worker noticed there was water around the base of a strainer. The location of the drain holes at an elevated point at the front of a sump meant that it was rare for a worker to enter water above gumboot height to undertake the task of clearing around a strainer. I am satisfied on the evidence that for the vast majority of occasions when a strainer was cleared, the water height was insignificant and well below half gumboot height. I am satisfied that the workers observed the strainer to determine if the water was above or around gumboot height before approaching the drain hole. If there was a risk that the water was above gumboot height or the strainer was missing, I am satisfied that the workers would approach the strainer from the basket of an ITC, whilst adhering to the requirements of the WiB Procedure. Strainers were also intended to provide some protection against bodily parts being sucked into drain holes.
The blocking of drain holes by the accumulation of rock and mud was a rare occurrence. The deliberate blocking of drain holes to allow work to be undertaken beneath drain holes was a rarer occurrence. It follows that the occasions on which it was necessary for the workers to unblock drain holes were also rare.
The methods described in evidence by the workers using water and compressed air were used because of the availability of these services on each level of the mine. Compressed air was available on each level of the mine to be used to power various pneumatic tools including the air pumps.
The use of explosives in the mine was an everyday activity. The use of explosives to unblock a drain hole was the subject of the JSA Procedure and other safety procedures specific to the use of explosives in the mine.
Workers were allocated tasks in pairs for safety reasons. When workers commenced at the mine they were placed with a more experienced worker as a means of on the job training and to learn work practices from more experienced workers.
Workers were allocated tasks in the context of the defendant's safety system. Where that task was unusual or the worker did not understand how to complete it safely, the CSA controls, the CSAfe Procedure and the JSA Procedure operated to prompt and/or require the workers to involve their supervisor in formulating a safe way of completing the allocated task.
The defendant knew that the dewatering system was inefficient and required improvement and as a result it embarked on the 8670 Pump Station Project. That project was the subject of a number of specific planning meetings.
I am satisfied that the defendant did not apply the MOC Procedure to the 8670 Pump Station Project. The prosecution submitted that this was significant because the defendant did not conduct a risk assessment, of which a JSA was the minimum standard, for the task of blocking the drain hole at the 8820 North sump and no detailed work instruction was prepared to prescribe how the drain hole should be blocked. The prosecution submitted that this resulted in later confusion and uncertainty concerning how the drain hole had been blocked and eventually put Mr Hern and Mr Booth in the position that they were required to devise a method of unblocking the drain hole by 'trial and error'. On the prosecution's case, this should have been avoided by the issue of a written procedure for how to unblock the drain hole.
For the reasons already given, I am satisfied that Mr Hern had sufficient information to perform the task of unblocking the drain hole safely, by operation of the defendant's safety system.
The prosecution's argument required the application of the MOC Procedure to each and every change involved in the 8670 Pump Station Project. Relevantly, the blocking of the drain hole in the 8820 North sump as a pre-requisite to the drilling of the drain hole in the 8790 North sump and the subsequent unblocking of the drain hole after the new drain hole had been completed. To apply that interpretation of the MOC Procedure, would require a JSA, as a minimum, to be undertaken for each and every element of the 8670 Pump Station Project defined as a change in the MOC Procedure.
I am not satisfied that the MOC Procedure was intended to operate on each and every change involved within a defined change because to apply it in that way would lead to the MOC Procedure being so onerous, that to apply it would not be reasonably practicable. The example of the application of the MOC Procedure to the change of haul trucks in the mine indicated that the MOC Procedure was applied at a high level, as a planning instrument to determine where possible safety issues may arise, which were then investigated in a systematic way. The MOC Procedure was not the subject of any significant investigation by the Inspectors. Its scope and operation were not explored in the Records of Interview that were conducted with the workers.
I will now turn to the individual elements pleaded in [17(b)] of the Summons.
Particular [17(b)(i)] required a risk assessment to be undertaken before blocking a drain hole. The Summons did not specify what type of risk assessment was required. The mine employed three types of risk assessment being a JSA, a formal risk assessment and a specialist team formal risk assessment. The prosecution contended that it could be reasonably inferred that had the risk assessments provided for by the MOC Procedure been carried out, that the pleaded risk would have been identified and the hazards controlled. On the assumption that a general risk assessment was required, the particular involves some speculation. I am not satisfied that had a prospective risk assessment been undertaken that it would have identified the matters that led to the accumulation of a large volume of water in the sump. For the reasons already given, I am satisfied that the defendant's safety system operated to inform the method that should have been used to unblock the drain hole. I cannot be satisfied that the relevant circumstances would have been identified during a risk assessment sufficient to predict how the water was to be managed when the drain hole was blocked.
As to particular [17(b)(ii)], for the reasons already given, a JSA should have been conducted before unblocking the drain hole. The defendant had in place the JSA Procedure which should have been applied in the circumstances to ensure that the risk assessment was undertaken. I am also satisfied that if Mr Hern and Mr Booth had involved Mr McMillan and Mr Cownie, as they had been instructed to do, the risk assessment undertaken would have extended to the management of the water to be released from the sump.
As to particulars [17(b)(iii) and (iv)], for the reasons already given, I am not satisfied that the reduction in the volume of water in the sump was reasonably practicable.
As to particular [17(b)(v)], for the reasons already given, I am not satisfied that the prohibition was reasonably practicable because it was not reasonably foreseeable that workers would enter the water in which there was a risk of submersion, including water of the height specified.
As to particular [17(b)(vi)], this is no more than a re-statement of the WiB Procedure, which was already in place, regularly followed, and properly enforced. The prosecution contended that I should not have regard to the WiB or WAH Procedures because the defendant did not produce them in response to a number of section 155 notices sent to it during the investigation. I interpolate that the submission is that the defendant admitted that the WiB and WAH Procedures did not apply to the task of unblocking the drain hole because the defendant was silent as to their existence. I reject that submission for the reasons that follow. First, there were a large number of section 155 notices sent during the investigation seeking a large volume of documents. The defendant has a reasonable argument to say that the section 155 notices relied on by the prosecution to base this argument were not all drafted in such a way that it was clear that the WiB and WAH Procedures should have been produced. Second, the factual account given by Mr Booth squarely raised the WiB and WAH Procedures. Presumably, Mr Booth's evidence was the reference point for all of the interviews undertaken with the other workers and the management staff at the mine. It appears that the investigators did not squarely ask for any work instructions relevant to working from a basket of an ITC during the course of the investigation. This was directly relevant to Mr Hern's training and how he might have applied that training at the time of the incident. Third, there were references in the materials produced to the investigators that referred to the WiB and WAH Procedures, including the responses to questions asked pursuant to section 155 compiled by Mr Howard and references to those procedures in other documents including the MSMP and the induction packages. Fourth, the evidence overwhelmingly points to the conclusion that the WiB and WAH Procedures existed, were implemented and enforced at the mine.
As to particular [17(b)(vii)], this was not the subject of much evidence in the case. It seems to have been a procedure developed entirely after the incident and not one that was used prior to the incident. The evidence is insufficient to satisfy me beyond reasonable doubt that the matter was reasonably practicable.
Taking into account all of the evidence, the requirements of particular [17(b)] involve the application of considerable hindsight. I am not satisfied that the adoption of the Sump Procedure was reasonably practicable to the criminal standard.

[56]

[18] Of the Summons [18] The Defendant failed to ensure, so far as was reasonably practicable, the provision of adequate information and instruction to Mr Hern, in respect of the task of unblocking the 8820 North sump drain, in particular in respect to: (a) the depth of water that was in the sump; and/or (b) the location of the drain hole; and/or (c) the equipment that had been used to block the drain; and/or (d) the procedure to use for unblocking the sump drain, including the plant, tools and equipment required for the task; and/or (e) a prohibition on entering the water at the 8820 North sump where the level of the water was above 'gum boot height' or the level of water could not be easily determined.

As is apparent for the reasons already given, I am satisfied that Mr Hern had most of the information required by this particular, prior to or during his first attempt to unblock the drain hole. That information had been conveyed to him through the operation of the defendant's safety system.
I am satisfied that Mr Hern knew the depth of the water from speaking to Mr Gaydon at the cross-shift meeting, and/or to others about Mr Gaydon's conduct on the previous shift. Alternatively, Mr Hern knew the depth of the water when he approached the drain hole in the ITC and used the scaling bar to find the drain hole.
I am satisfied that Mr Hern knew of the approximate location of the drain hole by the markings on the wall of the mine and that he actually located it in his first attempt to unblock the drain hole. On the evidence, I am satisfied that he could not reach the blast bags because they were too far down the drain hole taking into consideration the length of the scaling bar and the depth of the water.
I am satisfied that Mr Hern had been told by Mr Gaydon that the drain hole had been blocked with blast bags. Accordingly, Mr Hern told Mr Booth and Mr Walkinshaw that he was going to 'pop the balloon'.
I am satisfied that in his first attempt to unblock the drain hole Mr Hern was using appropriate equipment for the task. During the first attempt, Mr Hern would have realised that the scaling bar was not long enough and that he needed a longer instrument. I am satisfied that Mr Hern knew there were other suitable tools or implements available for the task.
For the reasons already given, Mr Hern knew of the risk posed by entering the water to unblock the drain hole. I am uncertain if declaring the prohibition would have had any impact on safety in the circumstances. At the time of the incident, Mr Hern was in breach of the defendant's safety system in a number of significant respects. First, he removed his underground PPE. Second, he rode in the ITC basket and alighted from it in contravention of the WiB procedure. Third, he failed to comply with the JSA procedure. I am satisfied that Mr Hern was aware that he could be disciplined to the extent of being terminated for these breaches of the defendant's safety system, the first two of which were deliberate. In the circumstances, I am satisfied that there was a significant possibility that Mr Hern would have gone into the water to retrieve the scaling bar even if he had been prohibited from entering the water.
I am not satisfied beyond reasonable doubt that the steps involved in this particular were reasonably practicable.

[60]

Causation

The principles to be applied were not in dispute and are set out at [197] to [199] above.
For the reasons expressed, I have concluded that the defendant did not breach its duty by reference to the particulars of breach pleaded in [16]-[19] of the Summons.
The Site Induction training package delivered to the workers at the mine included the statement that 'working safely is a condition of employment at the CSA Mine'. That training also provided that the defendant expected the workers to follow all CSA guidelines and procedures.
The Surface Induction included training on risk management including how to identify hazards that were hidden and/or developing. This training also set out the three types of human error, including slips, lack of knowledge to select the appropriate plan of action and violations which were defined as deviation from understood and accepted normal practice for whatever reason. This training dealt with the identification of the likely outcomes of failing to identify and control a hazard that included death and serious personal injury.
I am satisfied that from the training provided to the workers at the mine that they knew that the work in the mine was dangerous and that in order to prevent risks to their health and safety, that it was essential that they complied with the procedures that they had been trained in.
The defendant had extensively trained Mr Hern and the other workers at the mine in various procedures that were intended to protect them from being exposed to risks to their health and safety. The dynamic nature of the conditions in the mine were such that it was not possible for the defendant to foresee every scenario that the workers may face during the course of a day's work and the only available course was to train the workers in procedures, which if applied, would avoid risks to the workers' health and safety. For the reasons already given, Mr Hern deliberately failed to follow the WAH and WiB Procedures, the PPE induction, the JSA Procedure and failed to comply with Mr McMillan's instruction to involve him in the planning of the task. If Mr Hern had complied with these procedures and the instructions of Mr McMillan, he would not have been exposed to the pleaded risk.
Mr Hern also failed to follow the advice of Mr Booth. It was unnecessary to enter the water to retrieve the scaling bar. This was recognised by Mr Booth who counselled Mr Hern against doing so on a number of occasions. The risk to safety posed by the scaling bar going through the drain hole was minor. Contrary to that advice, Mr Hern did get into the water. Mr Booth also advised Mr Hern to put his harness on after he had removed his clothes. Mr Hern declined to do so. If Mr Hern had followed Mr Booth's advice he would not have been exposed to the risk or it would have been minimised.
Finally, Mr Hern put himself in close proximity to the drain hole when the water was released. I am satisfied that Mr Hern knew of the risk of being sucked into the drain hole when the water was released, but he did not act on that knowledge.

[62]

The Evidence of Dr Judith Perl

The Prosecution called Dr Judith Perl, Pharmacologist. Dr Perl is an eminent pharmacologist whose principal area of research since 1979 has been on the effects of alcohol and drugs on psycho-motor performance skills.
Dr Perl opined that it was highly possible that the alcohol detected in Mr Hern's blood and urine was produced by microbes synthesising with alcohol after death. Dr Perl relied on studies demonstrating that there was an enhanced risk of microbial synthesis of alcohol in bodies recovered from water. The internationally accepted sample for toxicological examination is femoral blood or vitreous humour. Vitreous humour samples are preferred because there is less likelihood of artifactual rises in drug concentrations due to post mortem redistribution. Bacterial decomposition in contamination is much more common in deceased persons who suffer extensive trauma or whose bodies are exposed to soil and soil contaminated water, for instance, drowning victims, particularly in rivers and dams. Significant alcohol concentrations have been detected in blood and urine samples of some drowning victims who were very unlikely to have consumed alcohol, for example, young children.
Dr Perl opined given the circumstances of Mr Hern's death, that is, drowning in muddy water, that the alcohol in his blood and urine could have been created post mortem. Dr Perl assumed that the sump contained a large number of microbes capable of generating alcohol. It is possible that swallowing water containing these microbes could have infiltrated the blood and tissues surrounding his gastrointestinal tract, resulting in the formation of alcohol after death, particularly given the autopsy was conducted five days after his death and Dr Perl was unsure about whether his body would have been refrigerated for the entirety of this time.
Dr Perl opined that even if Mr Hern's blood alcohol concentration was arrived at by pre-death consumption, there would not have been an impairment in Mr Hern's psychomotor skills to any appreciable degree.
On the basis that Mr Hern's blood alcohol concentration was arrived at by pre-death consumption, Dr Perl did not take significant issue with Dr Robertson's calculations of the number of standard drinks to be ingested to give rise to the blood alcohol concentration in his femoral blood.

[63]

Evidence of Dr Michael Robertson

Dr Robertson is a forensic toxicologist with over 25 years' experience. His doctoral research was conducted on post mortem creation of alcohol.
Dr Robertson agreed with Dr Perl that microbial synthesis of alcohol post mortem can occur. However, he contended that the examples used by Dr Perl to support her hypothesis, based on the studies cited by her, were not consistent with the circumstances associated with Mr Hern's death. Mr Hern did not experience major trauma that would have led to rapid contamination of the body compartments. Whilst he drowned, he was not in the water for an extended period of time, in fact it was a very short period of time in comparison to the studies relied on by Dr Perl, where the shortest period of submersion was approximately 12 hours. Dr Robertson opined, based on the cited studies, that 12 hours was the minimum period of time required for post mortem alcohol production.
Dr Robertson disagreed with Dr Perl's conclusion that the alcohol readings in Mr Hern's blood and urine were produced post mortem for the following reasons. He was recovered from the water within 15 minutes, his body was refrigerated shortly after his death, there was no evidence of bacteria transmigrating from his gut or lungs found at autopsy, the blood collected was femoral blood, there was no suggestion that the bacterial transmigration was so advanced that the bacteria contaminated Mr Hern's urine, and the presence of alcohol in both blood and urine with the urine being at a higher concentration was more consistent with ingestion of alcohol prior to death. Dr Robertson relied on medical records to demonstrate that there was some period of refrigeration of Mr Hern's body at the local hospital prior to it being transported to Newcastle.
Dr Robertson concluded that the presence of alcohol in Mr Hern's blood and urine was from pre-death alcoholic consumption. Based on this he calculated that in the hour prior to commencing work at 6.30pm, Mr Hern would have needed to ingest between three to seven standard drinks of alcohol to reach the blood alcohol concentration levels found in his femoral blood sample. The amount of standard drinks required to reach this blood alcohol concentration increase if the period of alcohol ingestion increased. For example, if Mr Hern had been drinking for a period of three hours up to the time of commencement of his shift at 6.30pm then a further three standard drinks would be required to reach the appropriate blood alcohol concentration.

[64]

Consideration of the Intoxication Issue

On this issue, I prefer the expert evidence of Dr Robertson, for the reasons that follow. First, the issue was more closely related to Dr Robertson's training study and experience. Dr Robertson completed his PhD on the accrual of post mortem blood alcohol. By contrast, Dr Perl was reliant on the assessment of peer reviewed publications by others, to hypothesise that Mr Hern's alcohol readings were produced post mortem. In this regard, Dr Perl paid more attention to the general possibility that alcohol could be produced post mortem and by assuming there was a high level of bacteria in the water rather than assessing if the circumstances in the present case could be compared to the studies in the literature. Second, the circumstances of Mr Hern's submersion do not correlate with the circumstances of submersion of the subjects in the studies Dr Perl relied on. Third, the higher urine reading compared to the blood level is more consistent with pre-death alcohol consumption. Fourth, the proliferation of bacteria in Mr Hern's urine required a level of sugar, described by Dr Perl as 'pre-diabetic'. There is no evidence that Mr Hern had such a blood sugar level and this impacts on the reliability of Dr Perl's opinion.
Dr Perl and Dr Robertson agreed on the assumptions required to extrapolate alcohol consumption, if it was assumed that Mr Hern's readings were a result of pre-death consumption as opposed to post mortem production. This resulted in the consumption of a range of between three to seven standard drinks in the hour leading up the commencement of the shift. The longer the period in which the alcohol was consumed, the more alcohol required to achieve the post mortem readings. By reason of the relatively low readings detected, I am not satisfied that at the time when Mr Hern entered the water there would have been any appreciable impairment of his physical or mental abilities.
It does not follow from my preference as to Dr Robertson's evidence that Mr Hern was in breach of the defendant's drug and alcohol policy. There is no evidence that Mr Hern was displaying any adverse effects of alcohol during the course of his shift on 11 June 2014. Whilst the opinion of Dr Robertson is persuasive, so are the objective facts that suggest that Mr Hern was not affected by alcohol at any time during the shift on 11 June 2014.
In all of the circumstances, I am not satisfied that the post mortem alcohol readings are significant to the causation issue.

Stephen James Orr v Cobar Management Pty Ltd

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