Now, I've seen this ending. A friend of mine came into an original print of The Heretic when a local Film Depot shut down. It's the original, untampered with cut until the last reel. The last reel has the Burton dies ending. I occurs to me that just the last reel was replaced for the US release (makes sense since it would be cost prohibitive to restrike all the prints), and the extensive recut was for the Euro market and TV.

I'd never seen the VHS release and I only saw glimpses of the movie on broadcast TV, which I why I thought the versions were similar, save for the ending.