Well, there are a couple other possibilities, however remote. Admin edits don't carry a timestamp, but I really don't think any admins have edited anything. Back-end edits wouldn't carry a timestamp. Again, you'd have to have.... well, more access than I have atm LOL
Could be that Who is actually a bona fide split personality or heavy drinker and he just doesn't remember what he said last night or last month.
But I think it's more likely that he's just trying to slander the admins so yenz won't trust us.
Good luck w/ that.