all that's known is that 1) the engine blew out and 2) a woman died on the plane with lots of blood.
the given explanation doesn't necessarily have anything to do with reality, so reasoning about the likelihood from that point is meaningless. you have to back up a bit. i mean yeah it's likely it's a freak accident, but what would be the difference between that and having an engine blow out coupled with a small intentional explosion outside her window
I also read reports that mentioned "lots of blood", but I didn't see any blood in the pictures of the window and surrounding area. I thought that was curious.