No, Dave himself is fine; a little weird but harmless.
Originally he had an account and forgot the password and started a second one. People started noticing how the second account was like the first one so people started asking if he was Dave (his first account was like Dave1967 or something). He was adament he wasn't but eventually he admitted he was and that he forgot his password.
Later another user popped up posting the exact same way only this time he stayed adament he wasn't Dave. So it became a thing to call him Dave every time. That account disappeared and now he's back and not only can you tell from the posting style, but his usernames usually have something from the old one. Like Dave1967 was the first, then he was Mike1967, I forget the third one, but now he's volnut67.