I have defended my PhD thesis yesterday. Can I ask a committee member for his feedback on my answers during question-answer session? My PhD is in computational Materials science. I successfully defended my thesis yesterday. However, I felt that one of the committee members was starting to get angry with my answers. I was trying to answer his questions, but his questions were very vague indicating that he clearly did not go through my thesis. Thus I had to answer his questions a bit elaborately, so that he could understand the reasoning behind my answers. I could sense that he was dissatisfied with my answers.

For example: He asked me, how confident are you about your theoretical model when comparing with the real world experimental results?

My answer: Since my model has A, B, C assumptions. It can never accurately predict the experimental/real world results.

His question: What would be your confidence level? What percentage?

My answer: It would be hard to put an exact percentage. But I would go with 90%.

He followed with an "okay".

Can I ask him directly about his feedback on my answers during the session?
This would depend somewhat on your general relationship with him. If he is relatively anonymous to you then it probably isn't worth the effort and you won't get the feedback you want. 

But if you know one another well, through coursework or other research (etc.) then it might well be worth a sit-down. You may have some misunderstandings and he may be able to help you clear them up. He may be able to point to directions for study or research. There are a lot of things. 

But if you approach it right, you also show respect for him and his ideas and that can lead to a better long-term relationship that might be profitable. 

And, it isn't especially uncommon that a committee member (even several) haven't read your thesis. A common question from committee members to advisors just before or after the defense is "You're sure this is ok, Jack/Jill?". The advisor nods affirmatively and all is well.