Looks like the line between paying a C.I. and criminal bribery isn't so fine after all. Thanks to Marc S. for commenting on this post and informing me that what the DEA agent did is in fact a crime. It's called commercial bribing in the second degree and in New York State it's a class A misdemeanor. Had the $1,000 offer been one cent higher, it would have been a felony. That makes me think that the guy offering the bribe knew the law a lot better than I did.
A person is guilty of commercial bribing in the second degree when he confers, or offers or agrees to confer, any benefit upon any employee, agent or fiduciary without the consent of the latter`s employer or principal, with intent to influence his conduct in relation to his employer`s or principal`s affairs.