Relevance of providing "warning" and having "reasons" before withdrawal in McPherson v BNP Paribas

Question

This question refers to the case MacPherson v. BNP Paribas IRLR 558.

Mr McPherson withdrew his claim on medical grounds. In paragraph 31 he appears to be implicitly criticised by the Court of Appeal for not providing BNP Paribas with a warning that he is thinking of withdrawing the case. It is listed as unreasonable conduct "that he had given the impression... that he was pursuing the complaint and allowed BNP Paribas to incur considerable expense in preparing the case on that basis while ... he had been considering with his GP ... the question of abandoning proceedings on health grounds. There was no no hint to the tribunal or BNP Paribas of this possibility before notice of withdrawal"

Why is it necessary to provide a reason for withdrawal?

In this case, what sort of warning could possibly have been given that withdrawal was being contemplated?

Are there any relevant practice directions?

Mr McPherson's other behaviour mentioned in the case is unreasonable but I fail to grasp the Court's point in this respect.

Answer 1

It seems that this conduct is a breach of estoppel. Basically, you are not permitted to cause people expense by engaging in conduct from which they can reasonably believe that you will pursue a given course of action when you do not intend to do so. In this case, the appellant caused the respondent to believe that he would pursue a case against them when he wasn't going to do so.

I have not read the entire judgement but it is clear that this is only one part of the unreasonable conduct; on its own it is difficult to see how this could support the costs order. I mean, if the appellant had indicated that he may withdraw due to health reasons a prudent respondent would still have needed to prepare a defence against the contingency that he didn't.