When McNulty activates the watch and stops time in the office, there's a shot of a woman at the water fountain and the water is standing still. A few seconds later, the water disappears and the woman's shadow is now on the wall.
During the conversation between McNulty and Joe the bartender in the first bar scene the position of the popcorn bowl, the beer glass and the ashtray repeatedly change.
When the helicopter is shown frozen in flight the blades are shown as a blur, the result of the rotor moving too fast to be caught by the camera's slower frame rate.
At about the 12:55 minute mark as McNulty is watching out of his window while stopping and starting time, a collection of shots from around the world. In one of the shots is what looks like a French policeman directing cars from the early 1930's. Then the next shot shows modern (at the time) cars on a freeway.