Res Judicata, French style: Wehrkamp-Richter v Louis Paul Guitay

Patent litigators all round
Europe have been flagging up
this decision for discussion

Several readers have forwarded to me the helpful note from Pierre Véron (Véron & Associés) on the recent French Cour de Cassation en banc ruling in Reginald Wehrkamp-Richter v Louis Paul Guitay, which I would have posted earlier but for the fact that I was ploughing through a backlog of work when I received my own copy of it.  This decision, handed down on 17 February, concerns the situation in which a patentee prevails on infringement and validity and obtain damages as a result of a final judgment against a first infringer. Subsequently, in proceedings against a second alleged infringer, the patent is revoked.

The Court ruled that a first infringer cannot claim the restitution of the damages he has paid because the binding and final decision on liability is res iudicata and is not affected by the subsequent revocation of the patent. Pierre has made the judgment available in English here and in French here. He has also summarised the decision briefly:

"The answer given in the 17 February 2012 judgment, handed down en banc by the full court (Assemblée plénière) is loud and clear: 

"Because the first infringer had been held liable for infringement by an irrevocable decision, the Cour d'Appel rightly came to the conclusion that the retroactive and absolute revocation of the patent… in a subsequent decision could not justify the restitution of the sums paid in pursuance of the decision on the infringement."

It is quite exceptional that the French Cour de cassation deal with a patent case en banc (it does so only when conflicting decisions from various panels have been reported or to prevent such conflict). According to its standard practice, the Court does not explain its decision in the judgment itself, which is very short (2 pages). However, detailed explanations (in French) can be found in the 24-page report prepared by the rapporteur, which is available on the Court’s website here and in the 15-page advocate general’s opinion, available on the Court’s website here. 

This question was discussed during the 14th European Patent Judges' Symposium held in Bordeaux, 16-20 September 2008, published in the EPO’s Official Journal, Special Edition 1, 2009, page 56, "A patent held in a binding ruling to have been infringed is subsequently revoked: what happens next?" (here), with national reports from Germany, the United Kingdom and France".

Thank you, Pierre, for this useful information.

Pierre's firm runs the French Patent Case Law website, here.