(a) First, a direction to order a 'split trial' is a matter of practice, not a matter of law.[72] Whether such an order should be made is ultimately determined by matters of fairness.
(b) Second, a critical factor is whether the evidence the plaintiff seeks to reserve is properly 'a rebutting case', or whether it forms part of the plaintiffs' own case.
(c) The question of who bears the onus of proof on an issue is not decisive as to who should lead evidence first.[73]
(d) A guiding principle for the exercise of the discretionary power is the extent to which the plaintiff would otherwise be obliged to prove a negative.[74] On the facts in Protean Holdings, Marks J regarded the extent to which the plaintiff would be required to do so 'highly pertinent and of considerable weight'.[75]
(e) Even where each party knows what it is that its opponent contends, to require the plaintiffs' expert evidence to be given first will require, at least to some degree, the giving of expert evidence in a factual vacuum.[76]
(f) A split trial order is less likely to be made where the issues the subject of the proposed split trial order are intertwined with other issues.[77] The extent to which the issues are intertwined is an important consideration.
(g) Where there is difficulty separating out the issues with respect to which the plaintiffs have the burden of proof, permitting that evidence to be led without the plaintiff also embarking on evidence to counter anticipated evidence of the defendant will be a factor against making a split trial order.[78]
(h) Consideration must be given to whether it is unreasonable to expect counsel for the defendant to cross-examine the plaintiff on certain issues while at the same time being prevented from cross-examining on others (the subject of the proposed split trial order).[79]
(i) Where the deferral of part of the plaintiffs' cross-examination may cause substantial disruption to the orderly conduct of the trial, or where it would likely be unfair to the defendant to require a piecemeal cross-examination, particularly where issues of credit are involved, a split trial order is not likely to be made.[80]
(j) The more serious the allegation the subject of a split trial application, the more likely the Court will favour such an order, particularly where exposure to criminal prosecution or civil penalty provisions are concerned.[81]