In the decision X ZR 19/20 “Tretkurbeleinheit” discussed a few days ago here, the German BGH provides a very interesting discussion on the nature and role of pleas and arguments in a patent nullity suit.
Technical judges in the German patent court are usually recrutited among the examiners of the German Patent and Trademark Office (DPMA). From their experience in patent application and opposition procedures, they are used to apply the principle of official investigation, e.g. that the court is entitled to investigate the facts of the case on its own initiative, i.e. without being bound to the submissions of the parties involved.
Though everybody is aware of the fact that the applicability of this principle in the nullity suit is very limited, it is the experience of the author of this not that the judges are sometines unable to resist to the temptation to look into parts of the documents other than those highlighted by the parties or to to assess the inventiveness of subject-matter base on combinations of prior art which had not been proposed by the plaintiff.
According to the BGH, this approach is incorrect.
With reference to the earlier decision X ZR 99/11 “Fahrzeugwechselstromgenerator”, the court judges that the typically unlimited and unmanageable prior art is transformed into a plea by the specific explanations as to which concrete contribution which part of which document shall make towards the alleged lack of patentability.
A document unaccompanied with indications of such concrete contribitions is not a plea or argument, whereas a new argument based on a document already on file is a new plea oar argument and therefore admissible only in the exceptional situatons defined in § 531(2) of the German Civil Procedural Act (ZPO).
The important consequence of this clearcut difference between new documents and new pleas is that the court is not entitled to develop its own arguments and indications relating to eventual relevant contributions of documents on file to the alleged lack of paetentability. Considering any such court-generated argument would violate the principles of impartiality and party disposition (Margin no. 36 of the decision, page 19, 3rd line from the bottom).
This does not necessarily mean that each and every possible line of argument based on every available document should be filed from the onset. The case as initially filed could wel focus on the most promising lines of argumentations.
Accounting for the principles established in the decision “Fahrzeugwechselstromgenerator” , the decisive point on time is the preliminary opinion of the patent court under § 83(1) of the German Patent Act. The parties should go “all in” if this opinion is negative to them because failure to do so could result in the foreclosure of new document of new arguments based on old documents on the 2nd instance.