Re: Decapitation speed record
It probably doesn't have anything to do with speed. I have to imagine it's something about our single frame advancement and replaying and re-editing a lot. Possibly some combination of single frame advancing outside of edit mode, and doing it in edit mode. I know you can make replays kind of spaz out if you hit shift+p a bunch of times in edit mode and then go back to normal frame advancement.
Hampa's probably got a better idea since he wrote/has access to the source code.