Carbone as Trustee for the S & N Carbone Family Trust v Mills

[This headnote is not to be read as part of the decision] The respondent (Mr Mills) granted the appellants (Carbones), under an Option Agreement dated 4 September 2012, an option to purchase a farm. The Carbones purported to exercise the option on 28 September 2016. The primary Judge held that on the proper construction of the Option Agreement the option lapsed on 4 September 2012 and that therefore the purported exercise of the option was ineffective. His Honour held that in any event the option had not validly been exercised because the Carbones had not paid outstanding amounts of interest by the date they purported to exercise the option. The Carbones sought leave to appeal. They accepted the primary Judge's construction of the Option Agreement. However they contended that:

• Mr Mills was estopped from denying that the period for exercise of the option continued until 4 October 2016; and
• Mr Mills was estopped from relying on the Carbones' failure to pay the outstanding interest. The Court heard argument on the leave application and the appeal concurrently. Granting leave to appeal, but dismissing the appeal Sackville AJA (Beazley P and Barrett AJA agreeing) held: (i) While Mr Carbone believed that the option would not lapse until four years from the date the Carbones took possession of the farm in October 2012, that belief was mistaken and had nothing to do with anything said or done by Mr Mills: [77], [80]. Con-Stan Industries of Australia Pty Ltd v Norwich Winterthur Insurance (Australia) Ltd (1986) 160 CLR 226; [1986] HCA 14; applied. (ii) The Carbones' argument in relation to non-payment of interest relied on what was said to be a breach by Mr Mills of an implied covenant not to hinder or prevent the fulfilment of the Option Agreement. This argument had neither been pleaded nor put to the primary Judge. It was therefore not open to the Carbones to raise the argument on appeal for the first time. Coulton v Holcombe (1986) 162 CLR 1; [1986] HCA 33; applied.

Judgment

1. BEAZLEY P: I have had the advantage of reading in draft the reasons of Sackville AJA. I agree with his Honour's reasons and proposed orders.
2. SACKVILLE AJA: This is an application for leave to appeal from a decision of a Judge of the Equity Division (Darke J). His Honour dismissed a claim by the present applicants (together the Carbones) for declarations and other relief based on the contention that they validly exercised an option to purchase a farm in northern New South Wales known as "Wolonga" (Call Option). The primary Judge held that the Call Option, which was created by an agreement in writing dated 4 September 2012 (Option Agreement), lapsed at 5.00 pm on 4 September 2016. Accordingly, his Honour concluded the Carbones' attempt to exercise the Call Option on 28 September 2016 was ineffective. [1]
3. In addition to dismissing the Carbones' claim, the primary Judge made declarations sought by the present respondent (Mr Mills) in a cross-claim. The declarations are to the effect that the Call Option lapsed at 5.00 pm on 4 September 2016 and that the Carbones had failed to exercise the Call Option before it lapsed.
4. There is now no dispute that on the proper construction of the Option Agreement the Call Option lapsed on 4 September 2016. Nor is there any dispute that in any event the Carbones had not complied with cl 15.1 of the Option Agreement, which prevented them from validly exercising the Call Option while certain interest payments were outstanding. [2] However the Carbones' draft notice of appeal challenges the primary Judge's rejection of two arguments advanced by them at the trial. Specifically they say that his Honour should have found that:

• Mr Mills was estopped from denying that the period for exercise of the Call Option continued until 4 October 2016; [3] and
• Mr Mills was estopped from relying on cl 15.1 of the Option Agreement. [4] The Carbones must make out both estoppel arguments in order to succeed on the appeal.

1. Mr Mills has filed a draft notice of contention in which he seeks to uphold the findings on estoppel on a ground not relied on by the primary Judge. Mr Mills' contention is that the Carbones failed to adduce evidence that they changed their position in reliance upon the representations said to found the estoppels. It follows, so Mr Mills argues, that even if the Carbones make out their attack on his Honour's reasoning, they cannot satisfy an essential element of a plea of estoppel.

Leave to appeal

1. Prior to the hearing, the primary Judge made an order directing that the hearing be limited to a determination of the Carbones' claim for relief founded on their purported exercise of the Call Option (together with the corresponding claim for relief in Mr Mills' cross-claim). In these circumstances, as the Carbones accept, they require leave to appeal from the orders made by his Honour. [5]
2. Mr Braham SC, who appeared with Mr Neggo for Mr Mills, did not oppose the grant of leave. As the substantive issues were fully argued, it is appropriate to grant the Carbones leave to appeal. However for the reasons which follow their appeal must be dismissed.

Events leading to the Option Agreement

1. In August 2012, Mr Mills was the registered proprietor of Wolonga and an adjoining property, Taringa. He had previously granted Johnchap Pty Ltd (Johnchap) an option to purchase Wolonga and had entered into a contract for the sale of Taringa to Johnchap. However, Mr Mills had formed the view that neither transaction was likely to proceed further and that he should seek another buyer (or optionee) for the properties.
2. On 10 August 2012, the Carbones, accompanied by a real estate agent, inspected Wolonga and Taringa. Mr Mills was also present. During the inspection and at a meeting later that day, negotiations took place as to the manner in which the Carbones might acquire interests in the two properties.
3. On the same day, Mr Mills' solicitor (Mr Cowley) sent to the Carbones' solicitor (Mr Wilson) an email attaching a draft contract of sale in relation to Taringa and a draft option agreement in relation to Wolonga. Shortly thereafter the agent sent to both solicitors a sales advice he had prepared.
4. Correspondence then took place between the solicitors concerning the terms of the proposed contract for sale and the proposed option agreement. Between 28 and 30 August 2012, Mr Wilson discussed the proposed terms with the Carbones. During that period Mr Wilson wrote to Mr Cowley confirming various matters that had been discussed between the solicitors and requesting certain amendments to the draft agreements. On 30 August 2012, Mr Cowley sent amended draft agreements to Mr Wilson, who responded that the drafts appeared to be in order.
5. On 31 August 2012, Mr Cowley forwarded to Mr Wilson a contract of sale and an option agreement for execution by the Carbones and exchange. On 3 September 2012 Mr Wilson requested a further amendment to the option agreement. This led to some handwritten alterations to the final form of the Option Agreement.
6. Counterparts of the contract for the sale of Taringa and of the Option Agreement were exchanged on 4 September 2012, the date each bears.
7. The Taringa contract of sale provided for the Carbones to purchase the property for $2,203,920. Completion was to take place four weeks after termination of the contract for the sale of Taringa to Johnchap.

The Option Agreement

1. The Option Agreement was expressed to be made between Mr Mills, described as the "Vendor", and the Carbones (as trustees of a family trust), described as the "Purchaser".
2. Clause 2.1 provided for the Call Option as follows: "In consideration of the Premium paid by the Purchaser the Vendor grants to the Purchaser or his nominee an irrevocable option to purchase the Property for the price and subject to the terms and conditions which are contained in the Contract." The "Premium" was defined to mean the sum of $386,967.00 and the "Property" to mean the farm known as Wolonga (cl 1.1(10), (11)).
3. Clause 3.1 of the Option Agreement provided for a Put Option granted by the Purchaser to the Vendor. The Put Option is not presently relevant.
4. The "Option period" was identified in cl 4.1 as follows: "The Call Option may be exercised by the Purchaser on or after the Call Option Commencement Date but before 5pm on the Call Option Lapse Date by giving Notice of Exercise of Call Option." The "Call Option Commencement Date" was defined to mean the date of termination of the option that had been granted to Johnchap (not the date of the Option Agreement itself). The "Call Option Lapse Date" meant "that date that is 4 calendar years from the date of this Agreement" (cl 1.1(3)).
5. Clause 7.1 stated that if the Call Option was not exercised before 5.00 pm on the Call Option Lapse Date the Call Option lapsed. It is now not in dispute that the effect of cl 7.1, as a matter of construction, was that the Call Option lapsed on 4 September 2016, four years after the date of execution of the Option Agreement.
6. Clause 8.1 required the Purchaser to pay the Premium to the Vendor on or before 24 September 2012. If the Call Option was exercised, the Premium was to be applied in part payment of the deposit payable pursuant to the "Contract", being the agreement for sale of land set out in Schedule 1 to the Option Agreement (cl 8.4).
7. Clause 11.1 provided as follows: "… the Purchaser may have possession of the Property on the conditions contained in Schedule 4 from the later of the following dates: (1) The date it pays the Premium; or (2) the date of this Agreement."
8. Clause 11.3 required the Purchaser to pay an occupation fee of $150,000 (plus GST) per annum. That amount was payable six months from the date of the Option Agreement (not the date the Carbones took possession). Payments of $75,000 (plus GST), adjusted for movements in the Consumer Price Index, were payable every six months thereafter, until completion of the Contract.
9. Clause 15 of the Option Agreement provided as follows: "15.1 If the Purchaser does not pay any monies payable to the Vendor on the due date for payment, the Purchaser must pay to the Vendor interest at the rate of 15% per annum on all moneys payable hereunder from the day on which the same are due for payment hereunder up to and including the date of payment and such interest shall be paid by the Purchaser to the Vendor together with such moneys payable hereunder and any exercise of the Option by the Purchaser will not be effective until and unless such interest is paid. 15.2 This clause does not In any way affect or prejudice the rights of the Vendor under this Agreement in respect of default by the Purchaser, including the right of termination of this Agreement." (Emphasis added.)
10. Clause 20 stated that the Option Agreement was conditional upon the parties entering into the contract for the sale of Taringa to the Carbones. Clause 24 provided that the Option Agreement was also conditional on the termination of the option agreement between Mr Mills and Johnchap.
11. Schedule 4 to the Option Agreement set out the terms on which the Purchaser was entitled to use the Property pursuant to cl 11.1 of the Option Agreement. The Purchaser was granted a non-assignable licence to use the Property and could do so only for the purpose of farming and grazing (cll 2, 6). The Purchaser's possession of the Property was non-exclusive with respect to the Vendor (cl 13.2). Schedule 4 did not specify the term of the non-exclusive licence but cl 11.3 envisaged that the Carbones would pay the occupation until completion of the "Contract" (that is the contract of sale that would come into existence on the exercise of the Call Option).
12. The terms of the Contract set out in Schedule 1 to the Option Agreement stated (cl 65.1) that the "Completion Date" was to be the earlier of: "(1) That date that is one calendar month after the completion of the sale of the Purchaser's Property, referred to in the Option; or (2) That date that is 48 calendar months from the date of the Option." (Clause 65.1(b) is rather curious because, on any view, the option was exercisable until the expiration of four years from the date of the Option Agreement. It is not likely that the date of exercise of the option and the date of completion of the contract brought into existence by exercise of the option would coincide. A possible explanation, although not one advanced by the parties, is that the expression "calendar months" (in cl 65.1(2)) was intended to mean "complete calendar months".)

Events after the Option Agreement

1. The execution and exchange of the contract for the sale of Taringa satisfied the condition specified in cl 20.1 of the Option Agreement. At about the time contracts were exchanged, Mr Mills' solicitor gave notice to the Carbones' solicitor that the option agreement between Mr Mills and Johnchap had been terminated. The Option Agreement thereupon became unconditional and 4 September 2012 became the Call Option Commencement Date. [6]
2. Despite the notification to the Carbones that the option agreement with Johnchap had been terminated, Johnchap subsequently lodged caveats over the titles to both Taringa and Wolonga.
3. On 12 September 2016, Mr Mills commenced proceedings against Johnchap seeking declarations that the Option Agreement and contract of sale between those parties had been validly terminated. The dispute between Mr Mills and Johnchap led to a delay in the Carbones taking possession of Wolonga pursuant to the Option Agreement.
4. The Carbones paid the Premium due under cl 8.1 of the Option Agreement on 26 September 2012. Accordingly, the Carbones became entitled to possession of Wolonga pursuant to cl 11.1 from 26 September 2012. [7]
5. Johnchap withdrew its caveats on 28 September 2012 and the Carbones' solicitor was notified of the withdrawal on 3 October 2012. The sale of Taringa to the Carbones was completed on 4 October 2012. [8]
6. As the primary Judge recorded, [9] there was a dispute as to when the Carbones entered into possession of Wolonga. They maintained that they did not take possession until 7 October 2012 (after Johnchap withdrew the caveats), while Mr Mills contended that they had actually moved into the homestead on Wolonga shortly after 24 September 2012. His Honour did not consider it necessary to resolve the dispute.
7. The Carbones did not pay the occupation fee due on 4 March 2013. On 17 April 2013, Mr Mills and Mr Carbone had a conversation in which they discussed payment of the outstanding occupation fee, including the interest payable. During this conversation, a discussion took place during which it was agreed that the "lease payments" or "rent payments" should be calculated from 4 October 2012 and paid on 4 April and 4 October each year. The parties were in dispute as to what, if anything, was said as to the time within which the Carbones could exercise the Call Option. The dispute is said by the Carbones to be central to their case on estoppel.
8. On 10 December 2013 Mr Mills sent a payment schedule to Mr Carbone under cover of an email marked "Carbone payment schedule Wolonga". The contents of the payment schedule are addressed later. [10]
9. On 14 September 2016, Mr Mills served a "Notice to Vacate" Wolonga on the Carbones. The covering letter stated that the Carbones had not exercised the Call Option by the Call Option Lapse Date of 4 September 2016.
10. On 23 September 2016, the Carbones' solicitor sent a letter to Mr Mills' solicitor as follows: "We refer to your letter of 22 September 2016 and advise that our client does not accept that the Option Agreement expired on 4 September 2012. Though the Option Agreement dated 4 September 2012 provides that it is to lapse 4 calendar years from the date of the Agreement we submit that the parties clearly understood the lapse date as being 4 October 2016 being four years from the date our client took possession of 'Wolonga'."
11. On 28 September 2016, the Carbones served a Notice of Exercise of Call Option. It is the validity of that Notice that is in issue on the appeal.

Primary Judgment

1. The primary Judge first addressed the Carbones' argument that the Option Agreement should be construed to provide for a "Call Option period" of four years running from the date the Carbones took possession of Wolonga. In considering this argument his Honour took into account the evidence of communications between the parties prior to the execution of the Option Agreement. [11] This required an evaluation of the conflicting evidence given by the Carbones, on the one hand, and Mr Mills on the other.
2. The primary Judge considered that Mr Carbone's evidence had been "significantly undermined" in cross-examination and that his account of the conversations therefore had to be treated with caution. [12] His Honour also had "misgivings" about the reliability of Mrs Carbone's affidavit. [13] By contrast, Mr Mills' evidence was given truthfully and was likely to be reasonably reliable. [14]
3. It was common ground that in the discussion that took place on 10 August 2012, Mr Carbone said that he needed a four year lease of Wolonga. [15] The dispute was whether Mr Carbone said (as the Carbones claimed) that they wanted a lease for four years "from when we take over".
4. The primary Judge did not accept the Carbones' evidence on this point. [16] Nor did his Honour accept that Mr Mills said that they would have an option to purchase Wolonga while they leased the property. [17] His Honour accepted Mr Mills' evidence that there was no specific discussion about when the option period would begin. However, his Honour was satisfied that Mr Mills agreed in a conversation after 10 August 2012 that the Carbones would have an option period of four years. [18]
5. His Honour made the following findings: [19] "75 It seems to me … that there was discussion about a four year lease, to which Mr Mills agreed, and there was also later discussion about a four year option period, to which Mr Mills agreed. … 76 … I am not persuaded that there was any discussion in August 2012 to the effect that the periods of the lease and the option would exactly coincide (so as to make them contemporaneous). Further, I do not accept that in the course of any of the conversations in August 2012 the parties reached any consensus to the effect that the [Carbones] would have an option to purchase throughout the duration of the lease, or that they would have an option period of four years commencing when they went into possession of the property. I do not think that Mr Carbone and Mr Mills descended to that level of detail in the conversations. 77 Had the parties turned their minds to the question, they may well have thought that the four year periods of the lease and the option would or should coincide, but the question was not the subject of discussion, and the parties did not reach any agreement about it."
6. On the basis of these findings the primary Judge concluded that:

• the Option Agreement did not incorporate oral terms to the effect that the Carbones would have a four year lease of Wolonga commencing from when they took possession of the Property and an option to purchase which could be exercised at any time throughout that four year term; [20]
• on the proper construction of the Option Agreement, the option to purchase lapsed at 5.00 pm on 4 September 2016; [21] and
• the Carbones' contention that the Option Agreement should be rectified to provide for the option to purchase to be exercised during the four year period from the date they took possession of Wolonga could not be accepted. [22]

1. The primary Judge observed that the Carbones' various estoppel claims rested largely although not entirely upon Mr Carbone's version of the conversation with Mr Mills on or about 17 April 2013. On Mr Carbone's case, Mr Mills represented and Mr Carbone agreed that the Call Option period had commenced on 4 October 2012 and would continue until 4 October 2016. The parties thereafter proceeded on the basis of a mutually held assumption to that effect. [23]
2. The most significant divergence in the accounts of the conversation was whether the parties had discussed the date the Option Agreement became "active" or "effective". Mr Carbone claimed that he told Mr Mills that the Taringa sale had settled on 4 October 2012 and that the Option Agreement became "active" on the same date. According to Mr Carbone, Mr Mills agreed, saying that Mr Carbone was "right". Mr Mills denied that there had been any discussion about the option itself, as distinct from the payments due under the Option Agreement. [24]
3. The primary Judge did not accept Mr Carbone's evidence on this issue. His Honour found that: [25] "The likelihood is that the discussion was concerned only with payments of the occupation fee, in particular the calculation of the fees and the timing of payments. That was the issue at hand. I accept Mr Mills' denial that there was any discussion about the option itself. There was no issue at that time about the exercise of the option, or the period within which the option could be exercised."
4. This finding was based in large measure on his Honour's lack of confidence in the accuracy and reliability of Mr Carbone's evidence and his greater confidence in Mr Mills' denials of Mr Carbone's claims. [26] His Honour also thought it was "telling" that Mr Carbone did not promptly inform Mr Mills of the alleged rental agreement when the Notice to Vacate was served on 14 September 2016. Moreover Mr Wilson's file notes contained no record of Mr Carbone giving him instructions that an agreement had been reached concerning the expiry date of the option. [27] His Honour rejected Mr Carbone's evidence that he told Mr Wilson about the agreement by telephone on 14 September 2016.
5. The primary Judge accepted that Mr Carbone told Mr Wilson on 14 September 2016 and on other occasions that he believed the option period extended to 4 October 2016. But his Honour found that Mr Carbone did not attribute his belief to an agreement reached with Mr Mills in April 2013. In his Honour's view, it was likely that Mr Carbone had formed the belief by linking the option period in his own mind to the date of settlement of the Taringa purchase (4 October 2012). [28]
6. His Honour found that the documentary evidence did not provide support for the existence of the asserted agreement. The Carbones had relied on the payment schedule sent by Mr Mills to Mr Carbone on 10 December 2013 which included a reference to "Settlement" next to the date of "4 October 2015". His Honour found that even if the date was an error and was intended to be 4 October 2016, the reference to a settlement on that date did not indicate that the Call Option could be exercised at any time before that date. [29] In any event, his Honour accepted Mr Mills' explanation that the date had been inserted by error in the wrong place on the spreadsheet. [30]

Primary estoppel case

1. The Carbones challenged two key findings of fact which, they argued, constituted the basis for the primary Judge's rejection of their primary estoppel case. The two findings were that:

• Mr Carbone's erroneous belief about the duration of the option period did not derive from any reliance on the conduct of Mr Mills; and
• Mr Mills did not say or do anything amounting to a representation to Mr Carbone that the Option period extended to 4 October 2016.

1. On the issue of reliance, Ms Fendekian, who appeared with Mr Edington for the Carbones, submitted that a plea of estoppel does not require the plaintiff to demonstrate the precise basis for his or her belief as to a state of affairs. In the present case, so Ms Fendekian argued, it was sufficient for the Carbones to establish that Mr Mills' conduct was a contributing factor to the belief. His Honour noted that in any event neither Mr Carbone nor Mrs Carbone gave evidence that had it not been for the August 2016 conversation they would have paid the outstanding interest on or before 4 October 2016. [35]
2. Ms Fendekian challenged two specific findings of fact relating to his Honour's conclusion that Mr Mills had not done or said anything amounting to a representation to Mr Carbone that the Call Option would not lapse until 4 October 2016.
3. First, she submitted that the primary Judge fell into error in rejecting Mr Carbone's account of the conversation of 17 April 2013. In particular, his Honour overlooked or paid insufficient attention to objective evidence supporting Mr Carbone's account. The objective evidence consisted of six matters: (i) The parties' dealings, including the conversation of 10 August 2012, did not distinguish between the Option period and the duration of the Carbones' proposed lease of Wolonga. (ii) Mr Mills accepted in his evidence that he had been concerned in September 2012 that the caveats unexpectedly lodged by Johnchap would affect completion of the contract for the sale of Taringa and could also affect the Option Agreement. (iii) The lodgement of the caveats created uncertainty in Mr Mills' mind as to what would happen, in particular whether the Carbones would be able to take possession of Wolonga. (iv) The Carbones paid the Premium on 26 September 2012 even though the caveats had not been removed by that date. (v) In April 2013 Mr Mills was uncertain as to the dates on which the Carbones were required to pay the occupation fee. It was common ground that the issue was resolved by the parties agreeing that the first payment was due on 4 April 2013 and subsequent payment should be made at six monthly intervals. (vi) The payment schedule provided by Mr Mills to Mr Carbone on 10 December 2013 did not distinguish between the duration of the Option period and the dates on which the occupation fee was payable.
4. Secondly, Ms Fendekian submitted that the primary Judge should have found that the payment schedule sent by Mr Mills to Mr Carbone in December 2013 constituted a representation to the effect that the Option period was four years from 4 October 2012 and thus the option would not lapse until 4 October 2016.
5. The Carbones' written submissions in chief contended that the primary Judge should have found that a conversation which took place between the parties on August 2016 was sufficient of itself to support an estoppel. That contention was abandoned in the written reply submissions.

Non-payment of interest

1. Ms Fendekian did not challenge the primary Judge's construction of cl 15.1 of the Option Agreement. Nor did she dispute that the Carbones had not paid all outstanding interest either when they purported to exercise the Call Option (28 September 2016) or on the date the Call Option (on their case) lapsed (4 October 2016). Ms Fendekian however, submitted that Mr Mills was precluded from relying on cl 15.1 because he had breached an implied covenant not to hinder or prevent the fulfilment of the Option Agreement. In particular, so Mr Fendekian argued, Mr Mills failed to send an invoice or otherwise inform the Carbones of the amount of interest outstanding. She conceded that this argument had neither been pleaded nor put to the primary Judge.
2. Ms Fendekian submitted in the alternative that the primary Judge should have found that Mr Mills' statement in August 2016 that the underpayment of interest could be "sorted out at the end" estopped him from relying on cl 15.1 in order to dispute the effectiveness of the Carbones' purported exercise of the Call Option.

Primary estoppel case

1. Mr Braham pointed out that at trial the Carbones relied on a number of arguments intended to produce the result that, notwithstanding the terms of the Option Agreement, the Call Option did not lapse until 4 October 2016. These arguments were primarily based on the conversation of 10 August 2012 during which Mr Carbone claimed that the parties had agreed that the Call Option would lapse four years "from when we [the Carbones] take over".
2. Mr Braham submitted that the primary Judge's rejection of these arguments has important forensic consequences for the Carbones' estoppel argument. The Carbones' case was that they believed well before April 2013 and indeed before execution of the Option Agreement, that the Call Option would lapse four years after they took possession of Wolonga. Mr Carbone gave evidence that he formed that belief by reason of the August 2012 conversation, not because of anything that happened in April 2013.
3. The 17 April 2013 conversation, even on Mr Carbone's account, did not mention the date the Call Option lapsed: on his account the only reference was to the date the option commenced ("became active"). It was a necessary part of the Carbones' case, so Mr Braham argued, that they understood what was said in April 2013 to convey that the option period was four years from 4 October 2012 because of Mr Carbone's pre-existing belief that the Call Option would lapse four years after the Carbones took possession of Wolonga.
4. Since the primary Judge rejected the case based on the August 2012 conversations (and there was no appeal from these findings), it followed that there could be no basis for a finding that the 17 April 2013 conversation conveyed a representation that the Call Option would not lapse until 4 October 2016. Under the terms of the Option Agreement, the date the Call Option lapsed was fixed by reference to the date of the Option Agreement, not the date the Call Option commenced (that being dependent on the termination of the option granted to Johnchap).
5. Mr Braham submitted that in any event there was no basis for overturning the primary Judge's rejection of Mr Carbone's account of the conversation of 17 April 2013. The finding was largely credit based. None of the six "objective" matters identified by Ms Fendekian suggested that the finding was glaringly improbable or contrary to compelling inferences. Nor did the payment schedule or the August 2016 conversation advance the Carbones' case on estoppel.

Non-payment of interest

1. Mr Braham submitted that the Carbones should not be permitted to raise for the first time on appeal the argument that Mr Mills had breached an implied covenant not to hinder or prevent fulfilment of the Option Agreement. In any event, so he argued, the evidence did not establish that Mr Mills had in any way prevented the Carbones paying the outstanding interest on or prior to 4 October 2016.
2. Mr Braham further submitted that there was no error in the primary Judge refusing to consider the Carbones' estoppel argument in relation to Mr Mills' reliance on cl 15.1, because the point had not been pleaded. Even if the primary Judge erred in this respect, the argument had to fail because there was no evidence that the Carbones had relied on anything said by Mr Mills in August 2016.

Principles

1. As there was no dispute between the parties as to the relevant principles, they can be stated very briefly. The elements necessary to create an estoppel by representation are as follows: [36] "(a) a statement or other conduct that constitutes a representation of fact; (b) its communication to the representee; (c) the representee's justifiable belief in its truth and his alteration of position in that belief; (d) an attempt by the representor to contradict his representation; (e) prejudice to the representee as a result of his alteration of position if contradiction of the representation were permitted." As Ms Fendekian submitted, a plaintiff who seeks to establish an estoppel by representation need not show that the defendant's conduct was the sole or dominant cause of the plaintiff's altered course of conduct. [37]
2. The High Court has explained that estoppel by convention is: [38] "a form of estoppel founded not on a representation of fact made by a representor and acted on by a representee to his detriment, but on the conduct of relations between the parties on the basis of an agreed or assumed state of facts, which both will be estopped from denying. … [T]here is no estoppel unless it can be shown that the alleged assumption has in fact been adopted by the parties as the conventional basis of their relationship."

The pleading

1. The Carbones pleaded a case based on both estoppel by representation and estoppel by convention. They alleged that Mr Mills represented to them, both before and after the Option Agreement was executed, that the Option period would commence (or had commenced) on 4 October 2012 and would continue until 4 October 2016. The plea of estoppel by convention alleged that the parties proceeded on the basis of a mutual assumption to the same effect.
2. The representation was said to have been made in the conversations of 10 August 2012 (predating the Option Agreement) and 17 April 2013 (postdating the Option Agreement). The Carbones also relied on the payment schedule prepared in December 2013 and a conversation that took place between the parties in August 2016. The pleaded estopped by convention was founded on similar allegations.

Mr Carbone's misapprehension

1. On the primary Judge's findings, Mr Carbone laboured under a misapprehension as to the effect of the Option Agreement, a misapprehension not shared by Mr Mills. Specifically Mr Carbone incorrectly believed that under the terms of the Option Agreement the Call Option would not lapse until four calendar years from the date the Carbones took possession of Wolonga.
2. The primary Judge observed that it was difficult to discern the basis for Mr Carbone's misapprehension, although his Honour thought that it may have reflected Mr Carbone's understanding that the Option period would not commence until Johnchap's caveats were withdrawn and the Taringa sale settled. [39] That understanding, coupled with Mr Carbone's apparent belief that the Call Option was exercisable during a fixed term of four years from its effective commencement, [40] would explain his genuine belief (in the events that happened) that the Call Option would not lapse until 4 October 2016.
3. Mr Carbone gave evidence that his understanding was "always" that it had been agreed that the Call Option would not lapse until four years from the date the Carbones took possession of Wolonga. On his account, he acquired that understanding before the Option Agreement came into force and retained the understanding thereafter. Indeed he said in his affidavit evidence that he did not turn his attention to the definition of "Call Option Lapse Date" in cl 1.1(3) of the Option Agreement (being the date four years from the date of the Option Agreement), but that if he had appreciated its significance he would have instructed his solicitor to amend the Option Agreement.
4. The primary Judge found that Mr Mills said nothing in his conversation of 10 August 2012 about the length of the Option period or the date on which it would lapse. There is no challenge to this finding. It follows, as Mr Braham submitted, that Mr Carbone's misapprehension as to the Option period, both before and immediately after the execution of the Option Agreement, had nothing to do with anything said or done by Mr Mills prior to the Option Agreement coming into effect.
5. Mr Carbone's evidence was that his belief as to the duration of the Option period was "confirmed" by the conversation of 17 April 2013. That conversation took place after Mr Mills provided Mr Carbone with calculations concerning the amount of the occupation fee that remained unpaid. Mr Carbone's account in his affidavit was as follows: "Mr Carbone: John, the interest rate that you have used is 15%. We have to be a bit more realistic because its 10% above the market rate. Mr Mills: No, that's why the interest is in there. It is to make sure that you have always got the money. Mr Carbone: The reason I have not got the money is because of an unforseen and uncontrollable drought event. This should be taken into account. Mr Mills: No, that's what it is and that's what you have to pay. Mr Carbone: The solicitors have also calculated default interest from 26 March. It has to be calculated from 4 April because that is when the payment was due. Mr Mills: Yeah, that's what I thought also. However when I queried them they told me it is calculated as per the agreement. Mr Carbone: No no. We took possession of the property on 4 October and 6 months' from then is 4 April. I can't pay the lease when I did not have possession. Mr Mills: Yeah, you're right. The lease payments will run from 4 April to 4 October each year. At some time during the conversation the following was also said: Mr Carbone: As we settled "Taringa" on 4 October the option agreement for "Wolonga" becomes active from 4 October also. Mr Mills: Yeah, you are right Sam. That's when everything happened and we got the caveat lifted."
6. Assuming, contrary to the primary Judge's finding, that Mr Carbone's account of the conversation was accurate, nothing was said by Mr Mills as to the duration of the Option period. The observation attributed to him, namely that the Option Agreement became effective from 4 October 2012, was made in the context of a discussion about the so-called "lease payments" (in fact the occupation fee payable pursuant to cl 11.3 of the Option Agreement). Even on Mr Carbone's account, Mr Mills was simply conveying his understanding of the date by reference to which the "lease payments" would become payable. Mr Mills addressed neither the duration of the Option period nor the date the Call Option would lapse. This is hardly surprising since on any view of the Option Agreement the Call Option was not due to lapse until a date well over three years from the date of the conversation. As the primary Judge noted, there was no reason for the parties to be concerned at this point about the date on which the Call Option would lapse.
7. If the conversation confirmed Mr Carbone's pre-existing belief as to the date the Call Option would lapse, it was because he was already under the misapprehension that the Option period was a fixed period of four years from the date the Carbones took possession of Wolonga. It was that misapprehension which led him (if it did) to interpret Mr Mills' comment about the date the Option Agreement "becomes active" as saying something about the date the Call Option would lapse. The misapprehension under which Mr Carbone laboured was not induced by any conduct of Mr Mills.
8. There may well have been other factors contributing to Mr Carbone's misunderstanding. The terms of the Option Agreement, while no doubt reasonably clear to a lawyer, may have been difficult for a lay person to follow or to remember. This is perhaps particularly true of the timing of the various events referred to in the Option Agreement:

• The "Option period" commenced on the date Johnchap's option was terminated but lapsed on a fixed date, being four calendar years from the date of execution of the Option Agreement (cl 4.1). Contrary to Mr Carbone's belief, the duration of the Option period was not a fixed term of four years but depended on the date Johnchap's option was terminated. Fortuitously that date happened to coincide with the date the Option Agreement came into effect.
• The Carbones' entitlement to possession of Wolonga arose on the later of two dates: the date the Carbones paid the Premium and the date of the Option Agreement (cl 11.1). By a handwritten amendment to the Option Agreement made prior to its execution the date for payment of the Premium was specified as 24 September 2012, rather than the date the sale of Taringa to the Carbones was completed (cl 8.1). The Carbones paid the Premium on 26 September 2012 and therefore became entitled to possession on that date. However, on their evidence, they did not actually enter possession of Wolonga until 4 October 2012.
• The first instalment of the occupation fee was payable six months from the date of the Option Agreement, not six months from the date the Carbones became entitled to take possession or entered possession of Wolonga (cl 11.3(1)).

1. Just as Mr Mills was not responsible for Mr Carbone's misunderstanding as to the duration of the Option period at the time the Option Agreement came into force, Mr Mills was not responsible for any confusion on Mr Carbone's part as to the terms of the Option Agreement. In short, to the extent that Mr Carbone failed correctly to understand the effect of the Option Agreement, his misunderstanding cannot be attributed to any conduct of Mr Mills. A self-induced misunderstanding cannot provide a basis for estoppel by representation. Nor can it provide a basis for conventional estoppel unless the misunderstanding is shared and acted upon by the other party.
2. For these reasons the Carbones' case on estoppel could not have succeeded even if Mr Carbone's account of the 17 April 2013 conversation had been accepted.

The 17 April 2013 conversation

1. As has been seen, the primary Judge did not accept Mr Carbone's account of the 17 April 2013 conversation. His Honour found that the only matter discussed during the conversation was payment of the occupation fee and that Mr Mills did not say anything to the effect that the Option Agreement became active as from 4 October 2013. It may not be strictly necessary to address the Carbones' challenge to these findings. But as the challenge formed the centrepiece of their argument it is appropriate to do so.
2. No party other than Mr Mills and Mr Carbone was present during the 17 April 2013 conversation. Neither Mr Mills nor Mr Carbone made a contemporaneous note of the conversation. Each was giving evidence some years after the conversation occurred.
3. The primary Judge took into account the failure of Mr Carbone, immediately after the Notice to Vacate Wolonga was served on 14 September 2016, to give instructions to his solicitor that the Call Option would not lapse until 4 October 2016. But Ms Fendekian did not dispute that the primary Judge's findings were largely based - as they had to be - on his Honour's assessment of the credibility of Mr Mills and Mr Carbone. His Honour gave cogent reasons for concluding that he had little confidence in the accuracy or reliability of Mr Carbone's evidence "even where he professed to have a clear recollection of what was said". [41] His Honour formed the view, having observed Mr Mills in the witness box, that he did his best to answer questions truthfully and that he was prepared to make concessions that might have been unfavourable to his case. [42] In these circumstances, the principles stated in Fox v Percy [43] apply. Therefore this Court should only interfere if the finding is contrary to "incontrovertible facts or uncontested testimony", or is "glaringly improbable" or "contrary to compelling inferences". [44]
4. As has been noted, the Carbones relied on six matters as constituting objective evidence inconsistent with the primary Judge's finding. These matters fall well short of establishing a sound basis for overturning the credit-based findings.
5. The first objective matter was said to be that the parties did not distinguish between the Option period and the timing of the "lease". In fact the Option Agreement did draw a distinction, in that the Option period commenced on the termination of the Johnchap option, while the Carbones' entitlement to possession arose on the date they paid the Premium. Even if neither Mr Mills nor Mr Carbone adverted specifically to the distinction during the 17 April 2013 conversation, their failure to do so is not inconsistent with Mr Mills' account of the 17 April 2013 conversation or with the primary Judge's acceptance of Mr Mills' evidence.
6. The second to fourth matters relied on by the Carbones overlap. Mr Mills agreed in cross-examination that he had been worried when Johnchap lodged caveats on about 6 September 2012 because the caveats might have affected completion of the sale of Taringa to the Carbones. He also agreed with the cross-examiner that he believed at the time that the caveats had to be removed before the Option Agreement "could really take effect". The cross-examiner's question was loosely framed but Mr Mills' answer reflected the provision in the Option Agreement stating that any default by him under the contract for the sale of Taringa was deemed to be a default under the Option Agreement (cl 20.2).
7. It appears that Mr Mills' principal concern in September 2012 was that Johnchap's caveats would prevent him from allowing the Carbones to take possession of the properties. That particular concern was resolved on 14 September 2012 when the solicitor for Johnchap indicated that the Carbones could have "free and unimpeded access" to the properties to plant crops. [45] It is not apparent why Mr Mills' concern in September 2012 that Johnchap's caveats should be withdrawn (as they were on 28 September 2012) should be regarded as inconsistent with his account of a conversation in April 2013 that took place nearly seven months later and dealt with a different issue.
8. The fifth matter relied on was the uncertainty that existed in April 2013 concerning the dates on which the occupation fee had to be paid. Mr Mills acknowledged that he was uncertain as to the position and sought advice from his solicitor. The issue was resolved by agreement between the parties. But that has little bearing on whether they discussed or referred to a separate issue (the duration of the Option period) that was not then of any concern to either party.
9. The sixth matter relied on as inconsistent with the primary Judge's finding was the payment schedule sent by Mr Mills to Mr Carbone on 10 December 2013. The schedule was in the form of a half-page spreadsheet, described by the primary Judge as follows: [46] "… There are dates shown in the left hand column. These are 4 October 2012, 4 April 2013, 4 October 2013, 4 April 2014, 4 October 2014, 4 April 2015 and 4 October 2015. In the adjacent column there appears, next to each date apart from 4 October 2015, a reference to a 'lease payment'. In the column adjacent to 4 October 2015 there is a reference to 'Settlement' and '$3,869,670 less dep. $386,967'. That is clearly a reference to the money that would be paid upon settlement of the sale of Wolonga if either the Call Option or the Put Option was exercised."
10. The primary Judge accepted Mr Mills' evidence that he originally prepared the spreadsheet for his own purposes to keep track of the amounts owed by the Carbones in respect of the occupation fee. Mr Mills inserted in the spreadsheet the dates for payment agreed on 17 April 2013. [47] He later sent the spreadsheet to Mr Carbone to show how he had calculated the outstanding amounts up to and including 4 October 2013, inclusive of interest.
11. The Carbones contended that the final date of 4 October 2015 in the spreadsheet was a mistake for 4 October 2016. Mr Mills explained that the mistake was not the insertion of an incorrect date, but placing the reference to "Settlement" opposite the date of 4 October 2015, rather than on a separate line below that date. The primary Judge accepted the explanation, which appears entirely plausible bearing in mind that the spreadsheet made no reference to any date after October 2015 on which the occupation fee might become payable.
12. In view of the primary Judge's acceptance of Mr Mills' evidence concerning the spreadsheet (a finding not challenged), there is no inconsistency between the content of the spreadsheet and his Honour's finding concerning the 17 April 2013 conversation.
13. As has been noted, the Carbones' written reply submissions abandoned reliance on the August 2016 conversation as an independent basis for establishing an estoppel. However, Ms Fendekian rather faintly suggested that the conversation was a further objective fact casting doubt on Mr Mills' evidence. The short answer is that even on Mr Carbone's version of the conversation, it simply concerned the time by which Mr Mills would "get [his] money" in view of the impending sale of the Carbones' Western Australian property. The conversation had nothing to do with the time within which the Call Option could be exercised.
14. For these reasons no error has been demonstrated in the primary Judge's findings concerning the conversation of 17 April 2013.

The payment schedule

1. Ms Fendekian relied on the payment schedule, independently of any earlier dealings between the parties, as conveying a representation that the Call Option would not lapse until 4 October 2016. There are two fundamental difficulties with this contention.
2. The first is that the payment schedule, on its face, did not make any reference to 4 October 2016. The spreadsheet identified the amount that the Carbones would have to pay on "Settlement", assuming that they exercised the Call Option. But the figure was placed next to the last date appearing on the spreadsheet, namely 4 October 2015. On an objective reading of the document this might suggest that it was prepared on the assumption that the Call Option would be exercised no later than 4 October 2015. But the spreadsheet cannot be read as conveying a representation that the Call Option would continue until 4 October 2016, unless exercised earlier.
3. Secondly, as was pointed out in argument, neither Mr nor Mrs Carbone gave evidence that they had understood the spreadsheet to convey the alleged representation. Nor did they give evidence that they relied on the spreadsheet in forming the view that the Call Option would not expire until 4 October 2016.
4. The Carbones' reliance on the payment schedule as an independent basis for establishing an estoppel by representation or conventional estoppel is misplaced.

Conclusion

1. The Carbones have not established that the primary Judge's rejection of their principal case on estoppel involved any error.

Non-payment of interest

1. Since the Carbones' principal estoppel argument must be rejected, it is not necessary to consider whether Mr Mills was precluded from relying on the Carbones' non-payment of interest as an independent ground for concluding that they did not validly exercise the Call Option. I shall, however, briefly address the Carbones' contentions.
2. The Carbones did not dispute that on the proper construction of cl 15.1 of the Option Agreement their purported exercise of the Call Option was ineffective unless they paid the outstanding interest on or before the lapse of the Call Option (on their case 4 October 2016). They also did not dispute that they had not paid the outstanding interest by that date.
3. The authorities establish that the courts may imply a duty on one party to a contract to co-operate in the doing of acts necessary to the performance by the other party of fundamental obligations under the contract. [48] The law also implies a negative covenant not to hinder or prevent the fulfilment of the purpose of the express promises made in the contract. [49]
4. The difficulty confronting the Carbones is that they did not seek to rely at trial on a breach by Mr Mills of an implied covenant. Had they done so Mr Mills might well have sought to adduce further evidence relevant to this contention. That evidence might have addressed, for example, Mr Mills' reasons for not sending an invoice to the Carbones and the extent of Mr Carbone's knowledge that the outstanding interest had to be paid before the Call Option lapsed. In these circumstances it is not open to the Carbones to raise the argument for the first time on appeal. [50]
5. In any event, on the evidence before the primary Judge it is difficult to see how Mr Mills could be said to have breached any implied term of the Option Agreement. The service on the Carbones of the Notice to Vacate Wolonga hardly prevented or hindered the Carbones from paying the arrears of interest prior to 4 October 2016. If anything, service of the Notice would have encouraged them to make the payment. Nothing in the Option Agreement obliged Mr Mills to send an invoice to the Carbones. Mr Carbone's evidence was to the effect that when the Notice was served he was aware of the "possibility" that interest was owing. Yet he made no inquiries as to whether Mr Mills was insisting on payment (despite earlier indications that Mr Mills wanted to be paid) nor as to the amount of interest due. It appears that Mr Carbone made no effort to pay off the arrears before 4 October 2016.
6. The Carbones' pleaded case did not expressly rely on the August 2016 conversation with Mr Mills as founding an estoppel that would prevent Mr Mills relying on cl 15.1 of the Option Agreement to defeat the Carbones' purported exercise of the Call Option. However, it is arguable that on a generous reading the Amended Statement of Claim can be understood as encompassing this estoppel argument.
7. Mr Mills agreed in his cross-examination that in the course of the August 2016 conversation he said that it would "be all sorted out in the end". But the comment was made during a discussion in which Mr Mills considered that he was being "fobbed off" by Mr Carbone in response to Mr Mills' questions as to when he would be paid. At best the comment was ambiguous.
8. As the primary Judge observed, neither of the Carbones gave evidence that their failure to pay the outstanding interest by 4 October 2016 was influenced by anything Mr Mills said in the August 2016 conversation. In the absence of such evidence the foundation for an estoppel is lacking.
9. It follows that if it was necessary for Mr Mills to rely on the Carbones' non-payment of interest to defeat their purported exercise of the Call Option, it would be open to him to do so.

Orders

1. The Carbones should be granted leave to appeal but the appeal should be dismissed. The Carbones must pay Mr Mills' costs of the appeal, including the application for leave to appeal.
2. BARRETT AJA: For the reasons given by Sackville AJA, orders should be made as his Honour proposes.

Endnotes

1. Carbone v Mills [2018] NSWSC 496 (Primary Judgment).
2. Clause 15.1 of the Option Agreement is reproduced at [23] below.
3. Primary Judgment at [172].
4. Primary Judgment at [173], [180].
5. Supreme Court Act 1970 (NSW), s 103.
6. Primary Judgment at [41], [110].
7. Primary Judgment at [42]. The Premium was paid two days late but nothing turns on this.
8. Primary Judgment at [123].
9. Primary Judgment at [125].
10. See at [92] below.
11. Primary Judgment at [48], [49].
12. Primary Judgment at [67].
13. Primary Judgment at [68].
14. Primary Judgment at [69].
15. Primary Judgment at [71].
16. Primary Judgment at [71].
17. Primary Judgment at [73].
18. Primary Judgment at [74]
19. Primary Judgment at [75]-[77].
20. Primary Judgment at [78].
21. Primary Judgment at [89]-[90].
22. Primary Judgment at [100]-[104].
23. Primary Judgment at [150].
24. Primary Judgment at [153]. Mr Carbone's version of the conversation is reproduced at [78] below.
25. Primary Judgment at [154].
26. Primary Judgment at [155].
27. Primary Judgment at [156].
28. Primary Judgment at [158].
29. Primary Judgment at [159].
30. Primary Judgment at [160].
31. Primary Judgment at [167]-[172].
32. Primary Judgment at [173].
33. Primary Judgment at [173].
34. Primary Judgment at [181].
35. Primary Judgment at [182].
36. K R Handley, Estoppel by Conduct and Election, Sweet & Maxwell, 2nd ed 2016, at [1-006].
37. J D Heydon, M J Leeming and P G Turner, Meagher, Gummow and Lehane's Equity Doctrines and Remedies LexisNexis Butterworths, 5th ed 2015, at [17-040(c)].
38. Con-Stan Industries of Australia Pty Ltd v Norwich Winterthur Insurance (Australia) Ltd (1986) 160 CLR 226 at 244; [1986] HCA 14.
39. Primary Judgment at [169].
40. Primary Judgment at [158].
41. Primary Judgment at [67], [155].
42. Primary Judgement at [269].
43. (2003) 214 CLR 118; [2003] HCA 22.
44. Fox v Percy at [28]-[29] (Gleeson CJ, Gummow and Kirby JJ).
45. Primary Judgment at [114]-[118].
46. Primary Judgment at [135].
47. Primary Judgment at [160].
48. Secured Income Real Estate (Australia) Ltd v St Martins Investments Pty Ltd (1979) 144 CLR 596; [1979] HCA 51 at 607-608 (Mason J, Gibbs, Stephen and Aickin JJ agreeing).
49. Peters (WA) Ltd v Petersville Ltd (2001) 205 CLR 126; [2001] HCA 45 at [36] (Gleeson CJ, Gummow, Kirby and Hayne JJ).
50. Coulton v Holcombe (1986) 162 CLR 1; [1986] HCA 33 at 7-8 (Gibbs CJ, Wilson, Brennan and Dawson JJ).

Amendments 28 February 2019 - fn 37: J D Heydon DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 28 February 2019