30Evidence as to the speed the vehicle was travelling came from very many sources. There is direct evidence as well as other evidence from which inferences can be drawn. As an example of the latter the Crown relies on evidence to suggest that the vehicle became airborne as it went over the crest of the dune.
31Expert evidence was called too. The witnesses gave their evidence concurrently after helpfully providing a joint document, which set out where one expert's opinion had changed, where they had reached agreement, and where they continued to disagree. Although Mr Alan Joy was called by the accused and Dr Raphael Grzebieta was called by the Crown, I detected no bias in either witness, and considered that they were both complying with their obligations to assist the Court.
32The experts differ by a very small amount as regards their calculations of the speed the vehicle was travelling as it went over the crest.
33Mr Joy calculated the speed at which the vehicle was travelling as it passed over the brink of the sand dune as being about 22.6 kilometres per hour. Dr Grzebieta agreed with the formula that Mr Joy used, but disagreed with some of the figures used in the formula. Dr Grzebieta considered that Mr Joy had overestimated the height that the vehicle had fallen and underestimated the horizontal distance it travelled. Using Dr Grzebieta's figures the estimated launch speed is 25 kilometres per hour. The difference in figures is explained by the experts taking their measurements from different sources. Mr Joy scaled the relevant measurements from a plan prepared by the police. Dr Grzebiata used measurements taken by a police officer at the scene. Neither method of measuring seemed to be inherently better or worse than the other.
34Mr Daily for the accused accepts that the speed of the vehicle was at least the speed calculated by Mr Joy. I am therefore prepared to proceed on the basis that the speed of the accused's vehicle as it went over the crest of the sand dune was at least 22.6 kilometres per hour.
35The other area of disagreement between the two experts concerns the certainty with which they considered that the accused's vehicle was airborne, such that all four tyres had left the sand, as it travelled in a downwards direction. Dr Grzebieta considered that it was "highly likely" that that occurred. Mr Joy said that he could not exclude the reasonable possibility that the vehicle was airborne and it was "line ball" on a balance of probabilities test.
36 What is perhaps more important than the question of whether the speed was 22.6 kilometres per hour or 25 kilometres an hour is this area of disagreement, namely whether the vehicle did in fact become airborne after it went over the crest. The evidence from sources other than the experts makes it clear beyond reasonable doubt that the vehicle was airborne. Eye witnesses said the vehicle became airborne and there is an absence of tyre tracks heading down the steep face of the dune suggesting that the tyres were not in contact with the steep face of the sand dune as the vehicle took its path from the crest of the hill to where it ended up at the bottom of the sand dune, on its roof.
37Let me at this stage explain the physical mechanism by which causing a vehicle to become airborne leads to it rotating forwards with the result that, in this case, the vehicle completely flipped over after its nose contacted the sand. As a vehicle drives up an incline its tyres would ordinarily be in contact with the surface underneath. As the vehicle reaches the top of that incline, the vehicle will tend to travel in the same direction with the front tyres of the vehicle leaving the surface if the momentum of the vehicle is sufficient. Once that happens the front of the vehicle commences to fall under the influence of gravity. But as the rear tyres remain in contact with the surface the rear of the vehicle does not fall. There is thus rotational force imparted to the vehicle. It will rotate in a forwards direction around its centre of gravity. Once the rear wheels also leave the surface and the vehicle is completely airborne, the vehicle continues to rotate. There is nothing to stop the vehicle rotating until it comes into contact with something to stop it.
38To summarise - driving a vehicle in such a way as to cause it to become airborne also causes that vehicle to rotate in a forwards direction as it falls.
39But of course there are other obvious consequences of driving a vehicle such that its tyres lose contact with the surface apart from rotation. You can't slow down a vehicle using the brakes when the tyres are not in contact with the ground underneath. The driver can do nothing to arrest the descent of a vehicle which is falling through the air. The driver can't change the path of the vehicle by steering. Once the vehicle is airborne the driver has no control over it in any way.
40As I alluded to earlier, the Crown relies on more than one aspect of the evidence in order to establish that the vehicle did become airborne. It relies on expert evidence. It relies on what witnesses did see (the vehicle being airborne) and what witnesses did not see (tyre tracks in the steep face of the dune). The Crown called evidence from witnesses who say they actually saw the vehicle become airborne after it reached the apex of the dune. It called evidence from witnesses who did not see tyre tracks in the steep side of the dune which should have been there, says the Crown, if the vehicle's tyres remained in contact with the sand before it flipped over.
41In contrast to the Crown case that the vehicle became airborne because the accused drove it at a dangerous speed, on 24 February 2009 the accused told police that he was driving very slowly indeed saying: "I think going, as I went over, I went so slow... "
42In answers following Q 241 in his ERISP the accused told police that as he was going up the approach side of the dune he was travelling about "walking pace", maybe a bit faster but that as he approached the top of the sand dune he slowed down "pretty much to a stop". Indeed the accused appears at Q193 to have attributed the collision to his travelling too slowly. This suggestion was not pursued at trial
43As it became clear during the course of the trial the defence case as advanced in questions put to witnesses involved a scenario, said to be consistent with the innocence of the accused, whereby the front wheels of the Suzuki broke through the surface of the sand at the very peak of the sand dune causing the front wheels to drop, imparting rotational movement to the vehicle. Under this scenario the front of the car was said to have dug in to the steep face of the sand dune towards its very top, this causing the vehicle to overturn.
44A number of things need to be noted about this alternative scenario postulated by defence counsel. Firstly it was not put, at least in clear terms, to either expert so that the expert could give his opinion as to whether such a scenario was a reasonably possible version of what had occurred. Secondly under this alternative hypothesis the vehicle did not become airborne, with the rear wheels at least being in constant contact with the sand until the vehicle overturned, and the front wheels being only off the sand momentarily. Thirdly I was asked to take into account an "unknown factor" or "environmental factors" which would have caused the front of the vehicle to dig into the sand towards the top of the steep face of the dune.
45I mentioned before the accused's interview with police. As I have explained in his ERISP he suggested that he travelled over the top of the sand dune, immediately before the vehicle turned onto its roof, at a very slow speed, indeed saying that he slowed right down "pretty much to a stop". It is clear however, that when I compare the evidence of those witnesses who saw the accused driving in the park that day and the evidence of the experts that the speed was at least 22.6 kilometres per hour, with what the accused told police about his manner of driving, the accused was misrepresenting what had occurred.
46Of course what an accused says to police in an ERISP is important evidence that a judge should take into account. But where it's been shown, without a shadow of a doubt, that the accused has told police things which are simply not capable of belief, the weight which must be given to the accused's version, must necessarily be significantly reduced.