It was on NCIS as well.
I nominate the SS shopper (SSS?) at our local produce and meat shop. The side for the meat shop is a big U with two islands in the middle. Traffic can only go in one way and out the other. However, you see some of the shoppers try to cut between the shoppers going the right way and the refrigerated cases. You need a lot of room to fit between there with a shopping cart.
Also, people who make holes in the shrink wrap over vegetable and fruit trays. I know those tomatoes, mushrooms, kumquats look delicious, but you can ask an employee for a sample. We saw a shopper opening a package today by punching a hole in the wrap with her fingernail, then putting the item back. We told the manager so they can clean and rewrap the package.
ETA: fixed a typo