'Mad Men:' What was he thinking?

For the DVR-ing masses, I'm going to be vague about the contents of last night's "Mad Men," except to say that there's a disturbing scene -- you'll know it when you see it, if you haven't yet -- that has already inspired a lot of Internet chatter. My question: How would you define the look on Don Draper's face when he's driving home, a few hours that scene takes place? I'd describe it as a mix of guilt, determination, and a sense of trying to convince himself that he had no other choice.