Being a pussy and a ton of miscommunication will be more affective than whatever the hell our strategy was last Saturday. If allow the other team to drive the lane 100 times untouched for a lay-up/dunk in one game, then you need to change your defense, no matter how last minute it may be.
That can all be done within the man defensive scheme as well. Change your ball pressure, how you defend screens, or your rotations on help, to name a few.
Zone defense is in the same category as playing with 2 fouls in the first half with oscar, he's just not going to do it (unless the situation is drastic, like in Lawrence). But I don't think any situation will be so drastic as to call for a zone defense, because he's a classic "man only defense" coach. I with he was a bit more flexible on that, but its obvious that isn't going to change, just like the foul thing.