I interviewed quite a few times when I was at google, and in very few cases would I deduct score for something that could be looked up online. I always started the interview with saying that if they wanted to look something up they could ask me, and if I didn’t know we could make it up and pretend the API existed. I frequently discussed this with others and they all did the same.

The point is absolutely not to find some technicality and use it against the candidate.