Nice marmot

Brandt: Mr. Lebowski is prepared to make a generous offer to you to act as courier once we get instructions for the money.
Dude: Why me, man?
Brandt: He suspects that the culprits might be the very people who, uh, soiled your rug, and you're in a unique position to confirm or, uh, disconfirm that suspicion.
Dude: So he thinks it's the carpet-pissers, huh?
Brandt: Well Dude, we just don't know.