Bunch O Balloons patent – Doctrine of Equivalence

On March 1 the Netherlands’ highest civil court, the Hoge Raad, rendered a decision in an appeal by Tinnus Enterprises c.s v.s Koopman.

The court of appeal decided that the patentee could not invoke the doctrine of equivalents because during prosecution the patentee removed first a claim element but later after a letter of the examiner put that claim element back in. According to the court of appeal the patentee is then bound to the strict literal language of that claim element because of the reasonable certainty of third parties. Such holding would be justified if the patentee would have defended or it would appear from the prosecution file that such literal reading of the reintroduced claim element was necessary to overcome a patentability objection by the examiner. However in this case the reintroduction had nothing to do with that the removal of the claim element meant that the patentee could not anymore rely on the priority date (because in the priority application there was no basis for a claim without the removed element).  As in the intervening year the patentee had come on the market his own invention would become prior art. So the patentee put the claim element back in to restore priority.
Why a third party could think that the patentee restricted himself in doing so to the strict literal meaning of that claim element remains a mystery.  The Court of Appeal did not give any reason why a third party could think that such literal meaning would be necessary for patentability requirements.
The decision of the Supreme Court means that any event during the prosecution can now be used by the lower courts to deny invoking the doctrine of equivalents. Moreover, the Court simply states that the reasonable certainty of third parties is at stake, then that is enough even if that is not credible.
It is clear that this is bad for patentees and innovation. The Netherlands is the only country in Europe with such a wide ranging interpretation of file-wrapper estoppel which estoppel possibility does not even figure in art 69 EPC and the Protocol.
It seems highly unlikely that the UPC will follow this.