If Casey does not play AB, Bryan looks like the ultimate idiot. So I think the biggest peril in Caseys job is creating his own vision for this team.
At this point he is executing Bryan's vision, its up to Bryan to pull the plug.
Also, if we clunked those 3's with other players and AB was on the bench, he would be questioned why we had our best 3pt shooter off the floor. You really can't win in this situation, the best strategy is to play AB and if he fails, the boss(GM) needs to plug in a different piece or change his vision.