>But I feel like a good interviewer (good is orthogonal to technical!) is likely to say "OK, so what is the runtime?", and "constant" and "O(1)" should both be on their list of keywords.
In that case, he was the CTO, though, and should know that "constant" is the same as "does not depend on the input size". (Though I'll admit I could have been unclear by trying to pre-emptively show how I knew what the next binding constraint would be.)
Agree with your points otherwise, but I still think the protocol should be (even if you're skipping through), to say something more like "let me note that down and I'll pass on your response" rather than imply it's not wrong because it's not in your list.
In that case, he was the CTO, though, and should know that "constant" is the same as "does not depend on the input size". (Though I'll admit I could have been unclear by trying to pre-emptively show how I knew what the next binding constraint would be.)
Agree with your points otherwise, but I still think the protocol should be (even if you're skipping through), to say something more like "let me note that down and I'll pass on your response" rather than imply it's not wrong because it's not in your list.