T 2378/13 - Not using the PSA, so disregarded?

Key points

• In this opposition appeal, the opponent as the appellant had submitted with its statement of grounds (in translation) " a variety of different arguments against the inventive step of [operative claim 1]. However, none of these arguments are based on the generally accepted problem-solution approach for assessing inventive step. Consequently, the complainant's allegations concerning the inventive step in writing are disregarded in this decision. During the oral proceedings, before the board, the [opponent] made attacks using the problem-solution approach, which the board acknowledged." The board finds that claim 1 is inventive. 
• The board does not indicate the legal basis in the EPC for disregarding the arguments in the opponents' statement of grounds and does not mention the opponent's right to be heard under Art.113(2) EPC. 
• A petition for review was recently filed (R5/19). However, admissibility of the petition appears a bit of an issue because the opponent (who was represented by an employee during the oral proceedings before the board; minutes) did not raise an objection under Rule 106 EPC.
• Addendum 26.07.2021: the petition for review was allowed.
  https://www.epo.org/law-practice/case-law-appeals/recent/r190005du1.html 
• As a comment, the legal basis for the Boards assumed power to disregard (i.e. declaring inadmissible) any timely filed inventive step attacks on the ground that they are not in the problem-solution approach format is not at all apparent to me, unless the Board, of course, understood that the opponent had waived its arguments during the oral proceedings.
• The statement of grounds of the opponent was drafted by a professional representative. It includes from page 19 three inventive step attacks which appear to each individually state the distinguishing feature and the objective technical problem (e.g. the attack on p.24 starting from D13), for each attack detailed comments are given on the (adverse) reasoning in the impugned decision.  Hence, I don't fully understand what the Board means with " Allerdings basiert keine dieser Argumentationen auf dem allgemein anerkannten Aufgabe-Lösungs-Ansatz zur Beurteilung der erfinderischen Tätigkeit" unless this Board means that an opponent may present inventive steps attacks in appeal starting from only one single document as "the" closest prior art.

EPO T 2378/13 -  link

5. Erfinderische Tätigkeit (Artikel 56 EPÜ)

5.1 Mit der Beschwerdebegründung hatte die Beschwerdeführerin eine Vielzahl von unterschiedlichen Argumentationen gegen die erfinderische Tätigkeit des der angefochtenen Entscheidung zugrundeliegenden Anspruchs 1 eingereicht, der dem Anspruch 1 des gültigen Hauptantrags entspricht. Allerdings basiert keine dieser Argumentationen auf dem allgemein anerkannten Aufgabe-Lösungs-Ansatz zur Beurteilung der erfinderischen Tätigkeit. Die schriftlich vorgebrachten Angriffe der Beschwerdeführerin bezüglich der erfinderischen Tätigkeit finden folglich in dieser Entscheidung keine Beachtung.

Während der mündlichen Verhandlung vor der Kammer hat die Beschwerdeführerin Angriffe unter Verwendung des Aufgabe-Lösungs-Ansatzes vorgebracht, die die Kammer gewürdigt hat.

5.2 Dokument E6 und allgemeines Fachwissen oder D2

Der Gegenstand des Anspruchs 1 ist ausgehend von der Offenbarung des Dokuments E6 weder in Zusammenschau mit dem allgemeinen Fachwissen noch in Zusammenschau mit der Offenbarung des Dokuments D2 nahegelegt.