c) Discretion misused by the department of first instance 

In T 1872/08 the opposition division used its discretion in an unreasonable way by refusing to admit the additional comparative tests. Therefore, the board decided to overrule the decision of the opposition division in this respect and to admit into the proceedings these comparative tests, which the patentee had resubmitted in its statement of grounds.

In T 1485/08 the board stated that the opposition division had not properly exercised its discretion in not admitting document (16T) for the sole reason that it was late-filed, without having examined its relevance or having considered any other criteria. Document (16T), which was resubmitted with the statement of grounds of appeal, was highly relevant as there were clear reasons to believe that it would prejudice the maintenance of the patent. The board decided, in the exercise of its discretion pursuant to Art. 12(4) RPBA 2007, not to hold document (16T) inadmissible.

In T 2716/19 the opposition division, when deciding on the admittance of D24, while using the correct criterion of prima facie relevance, had used it in an unreasonable way because it limited its assessment to the subject-matter of the then main request. It should have extended to the subject-matter of the auxiliary requests on file.