I recently had a couple of skype interviews with a well-known startup. First one went fine and I got good feedback but during the second one I was asked to share my screen & work on an IDE of my choice. That being something new, I didn't feel comfortable coding and though I did answer, the interviewer felt I was a bit (iffy) - I had written a conditional check & then changed it later. Interviews can get pretty hectic and it is way easier to say no to someone you don't even look at.