What is the test for reasonable and probable cause in false imprisonment and malicious prosecution?

Wade took issue with the answers given to these questions, arguing that the answers were perverse, given the evidence that was called at the trial. Schroeder J.A., speaking for the court, stated as follows: 47 The point must not be overlooked that in actions of false imprisonment and malicious prosecution, the question whether, on the facts, the defendant acted without reasonable and probable cause is for the judge, but the facts on which his decision depends must, if disputed, be found by the jury: West v. Baxendale, (1850) 9 C.B. 141. In that case it was stated by Maule J. at page 151: It was for the jury to say whether the facts pleaded were proved, and for the Judge to determine whether or not they amounted to reasonable and probable cause – reasonable and probable cause, not for suspecting, but for imprisoning the plaintiff. At page 152 Maule J. directed that the rule must be made absolute for a new trial on the ground of misdirection, stating: If the direction of the Lord Chief Justice in substance was, that the jury were to consider whether the facts stated in the plea were true, and whether they amounted to reasonable and probable cause, then, no doubt the direction was wrong. 48 In the present case the facts on which the decision must depend as to whether the defendant acted without reasonable and probable cause are not in dispute. Those facts emerge entirely from the defence evidence. There was, therefore, nothing to be left to the jury. Here the learned trial Judge left it to the jury to say whether the facts proved did in fact cause the defendant Wade to believe that the plaintiff had committed or was about to commit an offence for vagrancy. In other words, he was asking the jury to determine what effect should be given to the evidence going to the issue of justification, or the existence of reasonable and probable cause. That was the learned trial Judge’s function and not the function of the jury, and it would appear that in dealing with the question of reasonable and probable cause in his reasons for judgment, the learned trial judge felt that he was bound to yield to that finding of the jury, a finding which it was not within their province to make. (underlining added)