I'm a senior developer and I just interviewed 2 guys this week. I didn't feel the need to ask them anything about binary trees, big O, if they know how to implement a hash on the fly. And why not? Because it wasn't relevant to the job. The project they would be working is java code with a very large, already in place structure. If I got a programmer that decided to roll there own hash map instead of using the built in Java one then I would definitely be talking to them about not wasting time on shit like that. I sent them a small test to gauge the basic understanding of the language and syntax but it was mostly to gauge their ability to search for solutions and implement them because thats what the job is.
I think what the OP was trying to say was that sure, given 3 minutes with google he could have refreshed him memory with the all the big O notation of all the different types of searches that you learn in college but was that relevant to the job? Is that the programming he was going to do? If not, it's just interview fluff to make your self feel better.