We do the same thing as well. As long as the candidate can explain their abstractions in pseudo code we are good. We also keep to a 1-1 between interviewer and candidate so that the candidate isn’t intimidated.

I’ve interviewed at Facebook as well and although the interview was not successful I have never been nitpicked about syntax and compilabiltiy/runnability of my whiteboard solutions. I came off with a very healthy appreciation of the way they try to engage the candidate and reduce stress.