Imagine that you've been through two rounds of interviews for a job that involves some Perl coding. The first round includes a technical screen. You're given a whiteboard marker, and asked to sketch a solution to a fairly basic problem (one that gets at whether you can do simple stuff, like basic I/O, regular expressions, and some data accumulation and presentation using hashes.)
You pass the first round. You later hear that many prior candidates have crashed-and-burned during the technical screen.
In the second round, during a non-technical screen, you're back in the same room. You notice on the way in that the code now on the whiteboard isn't yours. During the course of the interview, you glance at the board a few times, first noticing that there is one outright bug, then that whoever wrote the code didn't understand autovivification, and then that they made a minor gaffe in a regex.
Do you point these problems out to the interviewer? Why (or why not)?