In T 195/84 (OJ 1986, 121) the appellant (patentee) objected at the oral proceedings that new grounds on inventive step were presented to which he had not had an opportunity to reply. The board did not share this opinion as the appellant had been aware that such prior art existed, and had thus had sufficient time to consider it in full. Furthermore, he had not requested any additional time and had not asked for an adjournment.
In T 327/92 the opposition division, at oral proceedings, had relied on a document as closest prior art against an amended main claim, which had been cited in the opposition against a dependent claim only. The board did not consider this a substantial procedural violation, as the patentee was dealing with a document which had always been part of the opposition, and could further examine this document at the oral proceedings.
Source: http://www.epo.org/law-practice/legal-texts/html/caselaw/2019/e/clr_iii_b_2_6_1_c.htm
Date retrieved: 17 May 2021