
I know you're probably in the field, but word about this will get back to you sooner or later, and I'd rather it be sooner.
Carrow was attacked while wandering outside, drunk on booze and potions. It was night before last, somewhere between the edges of the school grounds and the road to Hogsmeade. I've seen him myself and have spoken at length with the Matron. His injuries are quite extensive, but curiously, few of them were done by magic. It doesn't look like the work of highly trained fighters, but certainly fairly strong ones. Right now I'm considering the possibility that some unhappy seventh year students cornered him when he was pissed and kicked the ever-loving arse out of him.
The real problem here is that he's claiming it was Sirius Black who attacked him - two of them, to be specific. I've seen the man when he's been imbibing and I've no doubt that he's prone to hallucinations, and I wouldn't put it past a foolhardy student to dress up as the traitor to add insult to the man's injuries...but I don't want to dismiss anything out of hand. The fact that it was two Blacks, well, I can't help but think of how one Snape plus one Macnair equals two. Macnair, of course, wouldn't need a wand to physically demolish anyone, but he's better trained than what these injuries would suggest. Unless, of course, he was trying to make it look like the work of a student. Then there's the possibility of the Dementor handlers being behind this. Carrow was showing some rather intense interest in the creatures, it's possible that he was becoming a bother.
To top it all, Alecto is being a persistent claw in everyone's side, even going so far as to contact Lucius to complain about how no one on staff is taking the attack seriously. If you came in for even just an hour or two to question Carrow about what he saw, I think it'd go a long way in easing his sister's mind. Plus, it'd help me to have someone knowledgable around that I can discuss the case with. Tried doing that with Dawlish and he was a bit of a help, but there is a reason the MLE dropped him, I reckon.