Don't think it had anything to do with witchcraft and many of the "facts" which link it to witchcraft are completely untrue. The two big ones for example are the crucifix cut into his chest which actually wasn't. There's no reports of that from the time. The other one is the similarities to a witch murder from the 1800s, which actually had almost 0 simlarities, except they both involved a pitchfork. I think a lot of the witchcraft hype comes from the biography of the copper written years later where he sort of glammed it up a bit in my opinion.
I did a podcast episode on it, despite the fact it's almost definitely got nothing to do with witchcraft it's still quite an interesting story. Poor guy though, sounded like he did his life right and then came to that end.