In T 951/97 (OJ 1998, 440) the examining division introduced document D4 for the first time during oral proceedings. D4 had been mentioned in the European search report but had not been cited at any stage in the examination procedure prior to the oral proceedings. The board found that the half an hour adjournment of the oral proceedings before the examining division had been too short a period for an adequate analysis of the complex text of D4. It was clear that D4 was essential to the finding of the examining division in relation to inventive step; consequently, the decision was based on evidence on which the applicants had not had a sufficient opportunity to present their comments as required by Art. 113(1) EPC 1973 (see also T 492/03).
In T 783/89 the opposition division had presented the parties at the start of the oral proceedings with a new version of the main claim, giving them ten minutes to consider it. The board ruled that this had taken the appellants by surprise. Nor had the time given been enough to establish whether the amendments were allowable.