Google Software Development Engineer interview questions

It felt like a stress interview. The interviewer sounded pissed from the start and seemed like he was in no mood for the interview. He called me up and the first thing he said was "I have a coding question for you!". Then, he asked me to write a code for traversing a binary tree. As soon as I had given him the solution. He says that it will be all and slams the phone down. It was one of the weirdest interviews ever. I was surprised on how they were judging, because I did get the code right!!

How would you analyze a video clip to determine if it was shot by an amateur or a professional?