yeah both 3 things may happen. What happens in version #2 (Mary) is what happens every day and is of no consequence
Wrong, what Mary described was the result of good awareness and good aiki.
Terry Dobson stressed this repeatedly. To paraphrase him: If you're attacked with a knife in a dark alley at night, you've already screwed up - there's no aikido in putting yourself in that situation.
Incidentally, you can see some similar attacks that have happened not far from me in this article: chinasmack.com
Its rather instructive to see how it happens and what kind of timeframe you have to respond.