I know if I were an interviewer asking that question, I would have explicitly said "using whatever resources you have available... here's a terminal" if I had intended that. Instead, the question appears to be about a person's personal skills and knowledge.
Surely part of being "a totally kickass hacker" is your ability to use Internet resources effectively. I can see why you compare it with homework, but to me it's less abusive to do this for job interviews than it is for homework. Homework is designed to educate, so cheating is cheating. This is the real world.
Tangentially, I'm sure BUU didn't get to be Saint in (presumably) under two years by being a mediocre Perl hacker. Don't read too much into that arguement, though, I don't know how easy it is to troll your way to Sainthood 'round here.
I have to side with merlyn. In a job interview situation the interviewer wants to find out how you're likely to do on the job. The strategy, "Get someone else interested in doing my problem for me" doesn't work for the number of problems that you typically have at work, or for the kinds of problems that most of us get paid to do. Therefore your performance with that strategy says little about how well you'll do in practice.
A demonstrated skill at being able to locate and use documentation and modules is good. A demonstrated strategy of trying to get others to do your work for you is not so good.
Furthermore on your tangent, I wouldn't make any such presumption. XP here has to do with site participation, not skill level. For an extreme example look at TimToady.
But judge BUU for yourself. It is easy to take a look at BUU's top posts and ask what kind of skills and experience they indicate. From the content of his (presumably) best posts, I am not left with the impression that he is a particularly good Perl programmer. He knows how to ask questions that a lot of people will casually vote for. That's not the same thing.