I think it would also be very difficult for John to prove actual ownership of Judge Dredd. After all Pat as 2000AD Editor overruled his objections to Ezquerra's depiction of the character. Then there was the significant work that Pat and other early writers did to bash it into shape, in terms of fleshing out Dredd and his world. That's before you consider how the IP has grown over the years with the contribution of other writers.
Also IIRC what was written in TPO, Robinson's claim for her characters was actually based on having used some of them in her novels beforehand.
Also IIRC what was written in TPO, Robinson's claim for her characters was actually based on having used some of them in her novels beforehand.