I don't really think you understood this idea. Within the context of conference hosting, serving large glasses of freshly squeezed orange juice to that number

I don't really think you understood this idea. Within the context of conference hosting, serving large glasses of freshly squeezed orange juice to that number of people WAS a difficult domain specific question. He's less interested in the specifics of the answer to the question than he is in the thought process of the person answering it. Did they immediately say yes without considering it? If so they're conning you. They haven't thought out the problem and acknowledged the difficulty, so they'll say yes to anything, even though they can't deliver. Did they immediately say no, it's impossible? If so they're probably sub-par. They can't see a way to accomplish a difficult but achievable task. The WHOLE point of the question is judging whether the other party actually understands the domain well enough to recognize when a task is difficult, and then follow up by acknowledging that and asking better questions (like: What's your budget for that? Because it will be hard). The rest of your comment is spinning off into uselessness.