In T 952/00 the board found that the wrongful act, whether intentional or simply the result of culpable negligence, had to be judged in the light of the normal behaviour of an ordinarily diligent party. It also had to be the direct cause of the costs in suit. In the case in point, it transpired that the proprietor had culpably made inaccurate statements in the course of the proceedings. The board concluded that without those false statements the opponent (appellant) would not have been required to go to the expense of gathering further evidence. Its request for an apportionment of the costs it had incurred during taking of evidence after notification of the decision at first instance was therefore granted.

In T 269/02, according to the respondent, the appellant had been given sufficient opportunity before the opposition division to amend its claims to overcome the problem under Art. 123(2) EPC 1973. However, the appellant had chosen not to do this, with the result that the patent was revoked on this ground, rendering necessary the appeal proceedings, which dealt solely with the issue of amendment. Contrary to the respondent's assertions, the board stated that in cases such as the present, where the patent had been revoked in opposition proceedings, the appellant must be given the opportunity to study the decision of the opposition division duly substantiated in writing in order to enable it to decide on the formulation of appropriate requests for the appeal proceedings. In these circumstances, the board did not find that the appellant had abused or exceeded its legitimate rights, in a way which arbitrarily caused the respondents to incur costs which, in all fairness, ought to be reimbursed. The request for an apportionment of costs was therefore refused.

In T 916/05 the circumstances did not justify a different apportionment of costs. The fact that some of the arguments had not been presented before and could have been filed in oral proceedings before the opposition division, had such proceedings taken place, was in the board's opinion irrelevant and could not be regarded as an abuse of procedure. In fact, an appellant could not be prevented from choosing a different line of argument when making its case before a board of appeal.

In T 162/04 the respondent requested a different apportionment of costs because it had had to invest a considerable amount of time and effort in considering the numerous requests submitted by the appellant during the appeal proceedings. However, the appellant's requests were later withdrawn rendering the time and effort of the respondent, in its view, useless. In the board's judgment, such conduct did not amount to an abuse of procedure. Indeed, the conduct of the appellant, who by withdrawing the contested requests and by replacing them with other requests was apparently trying to overcome the objections which had been raised, was not as such objectionable but had to be considered as a legitimate defence of its case. The request for an apportionment of costs was therefore refused (likewise T 967/12).

In T 248/05 the board held that the alleged lack of clarity of the category of the claimed subject-matter and the possible associated additional costs which could be incurred by a clarification of this subject-matter would not justify appportioning the respondent's costs to the appellant. Firstly, the criticised elements of claim 1 and the alleged vagueness of the statement setting out the grounds of appeal were entirely irrelevant for the subject-matter of the appeal in point, i.e. the findings of the opposition division on added subject-matter. Secondly, lack of clarity of a claim or of a submission could hardly be regarded as an abuse of procedure unless this were intentional.

In T 854/12 the board decided that a different apportionment of costs was justified where procedural stages had needlessly had to be repeated because a lack of clarity as to the owner of the company purportedly acting as a party had been deliberately exploited or at least knowingly allowed to persist during the proceedings.