Armory of him now shows that they've removed all his ulduar achievements except normal difficulty 'shutdown'. Also he doesn't have gear in some slots - I suspect items earned via this exploit were removed from his toon too.

As much fun as this item would be, I would report it if I got it, not use it. It's the same as if your bank makes an error and deposits a million dollars in your account: if you go out and spend it you're an idiot, because sooner or later they'll realize their mistake and you ARE criminally liable if you spent any of the money received in error. There are recent occurrences of this in my local news, a woman received $150k by accident in her account and spent $30k of it before the bank caught up to her, now she's in jail for it.