I think admissions committee members have seen it all and understand that the people they meet with and talk to are bound to be nervous--some more nervous than others. I would think that if you gave great answers and impressed them, then you looked good in their eyes! 🙂
Don't worry about the nervousness so much. It's already behind you, and I've heard that people always remember their interviews as being worse than they actually were. Even the admissions committees people must know that they can't get know every applicant really well in the short time they have with them; I'm sure they don't think you're regularly that nervous. They know that interviews are a big deal to us and in trying to do really well in them, we might accidentally show we're scared/shy/freaked out.