I hate that sort of thing. It's embarrassing to catch people out in lies in that kind of situation. I was made to do something similar once-- someone was interviewing for a spot on my then-team, and my manager made me hand them a paper with a simple SQL statement on it and ask them to walk through it, explaining what it was doing. (Which is something I'd had to do myself when I interviewed.) Except this candidate didn't know SQL at all, apparently, and couldn't even begin to explain it. We all just sat there in embarrassed silence. It was especially horrible because he was an older guy, late middle-aged, too young to retire but definitely old enough to be a handicap in job searching. Just sitting there, knowing how desperate he must have been, and how crashingly obvious his lying about his experience was, and knowing that he knew that we knew how obvious his failure here was...uh, it was icky. Nobody burst into tears but I wanted to. I told my manager afterwards that I wouldn't do that anymore, if he wanted someone to explain SQL he could be the one to ask.