I'm sure that they're used to people feeling anxious and not answering perfectly! plus, not being from the US/prestigious school only makes it more impressive that you got an interview, they probably value that about you, it makes you a super unique candidate! Also if you want to speak with someone who went through the same process, many current students are on social media and they might be able to talk with you
I didn't get an interview but tbh I didn't expect one at all ahah I don't think I really fit the profile of a media lab student, I'd like to get more experience in tangible installations and research before applying again!
Hoping for the best for you!!!