Rep Power: 276

I wish I had a picture but I don't. My buddy came by last night with a rattle under his hood that got pretty loud when coming back down from a high rev. We found out that there was a bolt hanging out of the side of the alternator far enough to touch the bolt which holds on the clip which holds on the power steering reservoir. And I could almost get the bolt out of the alternator, it would wiggle back and forth about a full inch from side to side so it was almost at the edge but couldn't because it was up against the power steering clip which was bolted to the frame. But I got my fingers as far to the end as possible and couldn't feel any threads on it so I'm guessing it snapped clean off and the threads are still inside it, holding it together. This possible? He did have a broken engine mount which was causing his engine to rattle a little, there was a single stripped bolt on the mount. So he rethreaded the mount by a millimeter and put a new bolt in. However the alternator bolt happened before the did that, is it possible his engine twisted a little and put too much strain on this alternator bolt? Can that happen with only 2 of the 3 engine mount bolts on place?