At that point, "pinning" becomes a viable concept. Even though an option might be slightly out of the money on opex friday, it could be a good move to exercise over the weekend if you expect a gap at the opening on monday. After today's drop in everything, there will be lots of gaps on monday. Especially those sectors relatively isolated from today's bellweather tossers.
Angrad, did I get close on that one?
[that is three beers' thinking from a freshman]