IANAL but it might not be a bad idea to take a few minutes and write down who said what and when, while it's still fresh in your mind. Maybe even in some official company record ("captain's log").
I agree. If the situation escalates to the point where you can't avoid legal action (e.g., your contact accuses you of doing something corrupt), it would be useful to have a paper trail for your side of the story.
Ya never know . . .