The applicable legal principles
43In European Bank Limited v Evans (2010) 240 CLR 432; [2010] HCA 6 at [29] ("European Bank"), the High Court identified the approach to be taken in an inquiry for damages said to arise from the usual undertaking as to damages under the materially identical predecessor to UCPR Part 25, rule 25.8 (emphasis in original):
On the inquiry before Gzell J the first question was "What is the loss that is now alleged?", the second "Did that loss flow directly from the order of 18 May 2004?" and the third "Could the loss sustained have been foreseen at the time of that order?" The inquiry presented by the third question is an inquiry as to whether a loss of the kind actually sustained could have been foreseen. Contrary to the submission by the respondent, Mr Evans, the inquiry is not as to whether the actual loss suffered was foreseen at the time the undertaking was given.
44The first question ("What is the loss that is now alleged?") is factual. I shall return to it when considering the resolution of the issues.
45The second question ("Did that loss flow directly from the order?") raises an issue of causation. This was considered at length by the High Court in Air Express which was later approved by the High Court in European Bank.
46In Air Express Aickin J inquired into damages said to arise from an undertaking as to damages given in connection with proceedings before the High Court. His Honour primarily followed the approach of Brett LJ in Smith v Day (1882) 21 Ch D 421 to the effect that damages in the context of an undertaking should be assessed by analogy with the contractual principles set out in Hadley v Baxendale (1854) 9 Exch 341 [156 ER 145].
47This led his Honour to state the principle to be (at 266-267):
In a proceeding of an equitable nature it is generally proper to adopt a view which is just and equitable, or fair and reasonable in all the circumstances rather than to apply a rigid rule. However the view that the damages should be those which flow directly from the injunction and which could have been foreseen when the injunction was granted, is one which will be just and equitable in the circumstances of most cases and certainly in the present case. No doubt the view as expressed in the two decisions of the Court of Appeal [scil Smith v Day and Schlesinger v Bedford (1893) 9 TLR 370] does not constitute a rigid rule and circumstances may sometimes require a different approach. However it will in my opinion be seldom that it will be just or equitable that the unsuccessful plaintiff should bear the burden of damages which were not foreseeable from circumstances known to him at the time.
48His Honour went on to say (at 268; citations omitted):
It is important in all cases, and particularly in the present case, to bear in mind the distinction adverted to in many of the cases ... between damages flowing from the injunction and damages flowing from the litigation itself. There may not in every case be any difference between the two but, where there is a difference, it is essential that the damage flowing from the litigation should not be confused with the damage flowing from the interlocutory injunction. This is necessary required by the form of the undertaking itself.
49In Air Express, the undertaking had been given on the grant of an interlocutory injunction to restrain the original defendants to the action, the Commonwealth and the Secretary of the Department of Transport, from issuing permission to the defendant applicant and another company under customs regulations to import freighter aircraft into Australia. On the inquiry as to damages, Aickin J ultimately found against the defendant on the question of causation. His Honour held (at 282) that it was probable that once the action was commenced the Secretary would not have issued the permission and therefore the defendant had not established that the loss it had incurred from its inability to import the aircraft flowed from the grant of the injunction.
50On appeal to the Full Court of the High Court, Aickin J's approach was unanimously upheld. Three of the four judges comprising the Full Court expanded upon the question of causation. Gibbs J said (at 313; emphasis added):
The Court should no doubt scrutinize with care an assertion by a plaintiff that loss which has been suffered by a defendant has resulted from the litigation rather than from the making of an interlocutory order, since a plaintiff should not be allowed to evade payment of the price which he has agreed to pay for the grant of the injunction. In the end however the question becomes one of fact: did the making of the order cause the loss? The onus of proof must, in accordance with general principles, lie on the defendant who asserts that he sustained damage by reason of the order.
It was submitted on behalf of the appellant that it is enough that the making of the order should have been a cause of the damage, so that if both the making of the order and the continuance of the litigation are concurrent causes the undertaking will be applicable. However, in almost every case in which an injunction is granted the injunction will play some part in causing the party bound by it to act in accordance with its terms. To order a plaintiff to pay damages where it appears that the party bound by the injunction would have acted as he did even if the injunction had not been granted, would be to give the undertaking an effect obviously not intended. The party seeking to enforce the undertaking must show that the making of the order was a cause without which the damage would not have been suffered. It was further submitted that the onus lies on the plaintiff, against whom the undertaking is sought to be enforced, to disentangle any damage arising from the litigation from that which was caused by the making of the order. However, the onus of proof does not shift in this way; the defendant, who seeks to enforce the undertaking, must prove that the damage he has sustained was caused by the making of the order.
51Similarly, Stephen J (at 320) said:
It follows that it is for the claimant under an undertaking to establish by evidence, or by inference from evidence, a prima facie case both that the grant of the injunction was a cause of his damage and that but for it he would not have suffered that damage.
52Finally, Mason J said (at 324, emphasis added):
For this reason little is to be gained in the present case from an examination of the myriad authorities which deal with causation of damage in contract, tort and other situations many of which were pressed upon us in argument. We are better advised to look to the purpose which the undertaking as to damages is designed to serve and to identify that causal connection or standard of causal connection which is most appropriate to that purpose. The object of the undertaking is to protect a party, normally the defendant, in respect of such damage as he may sustain by reason of the grant of the interim injunction in the event that it emerges that the plaintiff is not entitled to relief. It is no part of the purpose of the undertaking to protect the defendant against loss or damage which he would have sustained otherwise, as for example, detriment which flows from the commencement of the litigation itself. That is loss or damage which the defendant must bear himself, as he does when no interim injunction is sought or granted. Consequently, it is for the party seeking to enforce the undertaking to show that that damage he has sustained would not have been sustained but for the injunction. (emphasis added)
53The third question posed in European Bank ("Could the loss sustained have been foreseen at the time of that order?") was explicated in that case. European Bank is authority for the proposition that the third question is an inquiry as to whether a loss of the kind actually sustained could have been foreseen. The inquiry is not as to whether the actual loss suffered was foreseen at the time the undertaking was given. In European Bank that question was decided by Gzell J's finding at first instance that the plaintiff knew that the injunction would deprive the defendant bank in that case from the opportunity of deploying its funds in the way which became the subject of its damages claim.