A patent that is limited during the course of the proceedings (even after the pleadings) is held to have been so limited ab initio if the limitation is duly registered.
When a European patent is granted and validated, an existing national patent loses its effect only for the invention claimed in the European patent.
The evidence for prior public use needs to be judged according to Dutch principles for evidence before the Dutch courts, i.e. on the balance of probabilities, corrected for the availability of the means of proof for the parties. If the prior public use was performed by this party, proof up to the hilt needs to be provided.