I'm sure you've noticed that the CPU doesn't take called third strikes. Today for the first time ever after years of playing this game I struck out the CPU on a called third strike. I pitched with Krukow against Ripken. Threw a big curve inside which just caught the edge of the plate. No swing, strike three. Anyone ever seen this happen?
I can't say with any certainty that I've seen it - I generally think of my strikeouts against the computer as being swinging (usually on the outside corner).
I think the situation you described is the one it can happen. Maybe also if the batter is set up way off the plate and you nip the outside corner. I'm pretty sure I've seen it happen, but I'd have to try to replicate.