When some idiots commit this kind of prank/crime, isn't it worse when you learn they're from one's own "side"?

I, for one, enjoy news of this kind much more when I can blame it on "those other guys." I'm sure that's how BB was feeling when he so belatedly found this bit of old news.

Why single out Amos, though? Why not, for instance, me? I feel left out...

I suppose it because Amos is not only persistent but also so thorough and diligent in assembling evidence and documentation for his arguments ~ can't get to him via reasoned debate, so only a cheap shot will do.