I've done the "confirm in e-mail" thing. I highly recommend it. I also brought in other folks on the request via email mentioning the name of the person and their request etc. Over communication is key, before you act. NEVER leave it up to just you even if it is typically a one man action

I'll never know what the full story was but the one time I had a request I wasn't comfortable with and communicated like crazy.... sales manager dude who was brought in with lots of fanfare moved on to other opportunities within two weeks.