It's super strange that the recruiter would have no understanding that alternate answers are possible, and would end the call abruptly claiming the candidate didn't know their fundamentals.

I've done this kind of phone screen for an entry level position at Google, and while the recruiter wasn't an engineer, they did have some basic knowledge of the concepts involved, and were able to prompt me with follow-up questions if I missed something or got a question half right. The questions themselves are not strange, it's the alleged attitude of the recruiter.