If I put up a wall specifically for the purpose of keeping someone out, and that someone takes out a spade and digs under it specifically to bug me, then that's still shit. And no, slandering someone isn't justified, but a spade is a spade is a spade.
And yeah, "the behaviour wasn't criminal" doesn't equate to "this person has done no wrong". If you're going to take tweets and tout them as Bad Essjay, pick ones that actually, you know, are Bad Essjay.