siriuswriter, you are probably closest to reality.
I am not sure if anyone who has posted realizes the type of personality it takes to be an actor of that caliber. People hear about this "being in character" all the time. They literally have to live up the character. Be in the moment. It is a state of being that can be hard to turn off and on. It's not like a switch. To truly explore the depths of the character that you are acting out, you have to think, act, feel, and want just as the character would to really bring the character to life. It may sound easy just reading my words, however, that's why very few people can actually make it to the upper echelon of acting.
When you're in that moment; in that character; feeling and thinking to the point that it is natural for the camera, you can very well stay in that moment and not experience very much of a "moment" dynamic. It can feel claustrophobic when you think about it. It can feel like nothing will change and your stuck being in that "person". It is not uncommon to end a day or two of filming an emotional scene with some tears of just distraught or emotional chaos.
Once he was out of the moment, back to what he should be, he could think much more clearly and he knows what he did was too far. Either that, or his PR person gave him verbal beat down and setup his apology. Also, reading that apology, it looks like I guessed it right. He was still "stuck" in character, caught up in the emotions.
I am quite sure someone like inimalist could better explain what I'm trying to convey. I still have a hard time with psychology.
BTW, Heath Ledger appears to have pushed himself to the absolute limits and beyond to "get into character" for the Joker. He actually pushed beyond his limits and never recovered.
Don't judge people so harshly. This man doesn't have the same type of mental state or personality that we are accostumed to as normal.
I can't remember which actor said it, but he said something like, "It takes someone truly insane to want to be an actor."
I think Mr. Bale learned something from this. I didn't lose or gain any respect for him as an actor. He is still one of my favorite actors. I don't agree with his actions. However, I blew up today, myself, while talking to my boss about a coworker who had just blown up on me, so how can I judge him in anyway?