This wasn’t an insult.
I didn’t say (or even imply) that he rapes little boys. I simply asked if he can prove he doesn’t. It wasn’t a personal attack. I can see how you would read it that way, but I was simply asking how he could prove any negative; I could just as easily have said, “Can you prove that we aren’t being watched by a giant hairy monster?”, or whatever.
If that wasn’t an Official Warning, then fine, forget it, no big deal, etc.
If it was, I wish to appeal.
That’s all.
This would have been a better choice.
I can’t stand it when people insist on someone proving a negative.
Prove it! 
I knew what you meant. It’s just your analogy was a little jarring at first sight.
Prove that I can’t prove it. 
That was the idea. It wasn’t an insult, though. It was an honest question.
I have no idea whether diggleblop does anything of the sort, and I’m willing to give him the benefit of the doubt, naturally. I was just trying to show him how ridiculous his own question was.
This.
…
That’ll work. Thanks, G.
Closed per the request of the OP.