Even a simple programming question can stump someone not trained in it. I've seen people who (supposedly) have computer science degrees fail on FizzBuzz.
In the end, it makes some sense to "talk shop" about programming issues. If they can't follow, it's probably not a good idea to hire them.
From this thread you'll find people that will reject someone with 10 years of experience because of failing Fizzbuzz in the conditions of an interview. It's not always used to talk shop. What I say is that there are things that are probably more statistically significant that questions with gotchas.
So? I've interviewed people with graduate Computer Science degrees who couldn't program a for {...} loop. Blew my mind, but it happened enough times that it doesn't surprise me any more.