Art. 104(1) EPC), which happens very rarely.
In the case T1071/06 the board had issued a preliminary opinion indicating that a document D0 would be considered as the closest prior art and the preliminary view was that the claims were inventive over D0. In response to this, frustrating punch, the opponent/appellant indicated one month after receipt of the summons that it would not attend to the oral proceedings.
The patentee/defendant attended to the oral proceedings alone and requested to impose the costs for the preparation and attendance to the oral proceedings to the appellant because the remaining issues could have been resolved in writing if only the opponent/appellant had given up earlier.
The board found that the appellant's behaviour was not abusive but that it is fair to grant each party the right to re-consider its case after receipt of the preliminary opinion. Besides, the oral proceedings would have been expedient in any case to resolve the remaining issues.