"Search incident to arrest" is not unlimited. It can be done, but only for certain purposes, such as obtaining weapons or preserving evidence. Did the pigs overreach here? Did they read a book that they didn't have a warrant for? Did they time the search wrong, and do it before he was arrested? Did they question him after the search, which would make least one of the two was unlawful?

We don't know, because the newspaper didn't bother to link to the court filing. So anyway, some of what you said was inaccurate, but for most of it, we just don't know what is on the record.