For one thing, the claims he made -- repeated as often and in as many variations as they were, in the tone he made them, and read in the context that they were usually read -- are "close enough for government work"; i.e, I think it's quite arguable that they *are* tantamount to an "appeal to action", albeit ever so slightly in-direct.
Secondly, the above only goes for his writings. He was also a very popular speaker in certain circles, and neither you nor I can know for sure what he said there... But would you want to bet that it *didn't* go a step or three farther than he dared do in his printed writings (which are and were publically available to law enforcement as well as "fellow" historians)?
Good riddance to the arsehole, say I. My only complaint, if any, would be that it took them so frigging long... WTF were they waiting for; for Arnie's old pal Kurt to die, perhaps? (Yeah, yeah, I know, they only happened to nab him by coincidence; presumably, he hasn't kept a very high profile in Austria lately... But couldn't they have had him extradited from Britain or France or whereverthefuck he'd been hanging out?)
Well, no, that's not my *only* complaint: Also, they should have put him away for a lot longer than the three years or whatever it was that they gave him. The rest of his natural, preferably.