Well they asked first so "no smoke with out fire eh" putting it in writing gives the impression that they have something to hide.
Over zealous/incompetent HR is probably the correct answer.
Seriously if you where a cop questioning some one and they blurt out I want to do a deal at the start of the interview what woudl you think
Normally in NCIS when the person getting interviewed by Jethro asks for a deal - they are the perp.
Or they have an overzealous HR person or lawyer.
Or any number of other things.
Of course they might also be a bunch of criminals, but I don't think an agreement like that implies anything in either direction.