I think if they are asking, then they are expecting you to be honest. Now, they probably won't be expecting what you're telling them, but you may never get another chance this year to lay it all out in front of them. And, if they don't necessarily believe you or they think that you are exaggerating, then they've got a few weeks to test him out, either in an attempt to use your information to try to find out where he really is or in an attempt to refute what you say and label you as a PITA. Unfortunately, you can't control what they do with the information. All you can do is give it to them.
BTW: If I were you, I'd probably make a photocopy of the information I give them, just to make sure I have a paper trail in case/when further advocacy is needed.
