Disc him a miss.

Originated on the US Marine Corps Rifle ranges to indicate the shooter missed the target. A "disc" is a metal disc 12" in diameter with one side painted red, the other white attached to a 6 foot wooden pole. Depending on the location of the disc on the target, it told the shooter what the score was for that shot. A miss was indicated by moving the red side of the disc back and forth in front of the target. The Marines from Marine Corps Security Force Company, Charleston, SC started using the term when another Marine screwed up or did something unpopular.

Dude, did you see Smith mess up that inspection?

Yeah, disc him a miss.