The Board of Appeal of the European Patent Office (EPO) has commented on this in its decision T 844/18 (Crispr/Cas) and continues its previous line:
For an effective claim of priority of an earlier application (with several applicants) by only some of the applicants of this earlier application in the form of a subsequent application, an effective transfer of the priority right is required. This must be transferred from the remaining applicants of the earlier application to the applicants of the subsequent application.
This was not the case here, so that the priority claim was ineffective and finally intermediate publications “became” novelty-damaging.
This is because it was also a question of determining “everyone” who is entitled to a right of priority under Art. 87 EPC. This is based on the acting persons who performed the act of filing the patent application (para. 108 of the decision), regardless of who made the actual invention. The EPO performs an “identity of applicants” test, so to speak.
In addition, it has been confirmed that the EPO is entitled to examine priority at all.