[daenz]

There are plenty of ways to get to the bottom of what a candidate knows without resorting to unreasonable questions. What you're really testing for is a candidate's patience for being toyed with.

[lazide]

Or the candidates ability/willingness to bullshit in order to not look ignorant or unskilled in something.

Which is actually useful to know, even if this method would be a dickish way to do it.