I had completely forgotten this incident until just now, and it's a good one.
Me and a friend went into a grocery store once to grab a few items, and my buddy was really stoned. So stoned in fact, he completely forgot he had a bag of bud in his jacket pocket. We get to the register, fortunately the cashier was a kid and no other customers were in line. He goes to pay for the items, and rather than pulling out his wallet to pay he pulls out the weed on accident. Then he stands there for about 3 seconds before realizing what he had done, says "Whoops"!, and then proceeds to finish the transaction as though nothing had happened. Meanwhile, me and the cashier couldn't stop laughing.