At the beginning when Wellman is writing the license plate in the notebook, the close-up has him wearing a glove while the wide-shot he is holding the glove with his left hand.
When Wellman arrives at LAX during daylight, he opens a personal locker and looks at the contents of an enclosed bag. His watch, on his left wrist, seems to read 3:45, or, if upside down, 9:15. Yet, Bosley seems to already be at lunch. A bit later, the close-up of Charlie's watch reads 1:00 PM. (Bosley had already had lunch, talked to the Angels in the office, and started his "game" with the Angels at about 12 noon.) Ellen even says, "Well, I'm lunching with a friend."
BTW, regarding Wellman's watch at the airport, later in the show Charlie tells the Angels that Wellman arrived at 10:45 that morning. Thus, 3:45 or 9:15 does not match.
As Ellen drives Bosley's car, in the close-ups of both, she appears to be driving on a pier (benches, metal railing and ocean). Yet, when Bosley turns around to look at the trailing Wellman in a Mercedes, the next clip shows Bosley's car from behind... it is on a city street. Then, in the next clip, Bosley's car is back on a pier, or close to it.
In the final shootout scene under the pier, there is person walking behind Kelly in the distance. In the next shot in that direction, that person is nowhere to be seen.
When Bosley and Ellen go to Moby's Dock for a drink after being shot at, they order "a Chablis" "...and a Chablis". When the waitress brings their drinks, she serves Bosley a clear liquid, over ice in a rocks glass. Then, when shown from Lawrence Wellman's spot at the bar, Bosley's drink appears the same color as Ellen's, and when shown from over Bosley's shoulder, his drink is colored and there is no ice in his glass.
In a common error for the time, Lawrence Wellman (James Sikking), uses a revolver with a silencer. However, because a revolver allows gas to escape from the gap between the cylinder and the barrel, a silencer is less than useless because it would affect the balance of the handgun for no benefit.
After the arcade (carousel) scene, Bosley and Ellen walk down to the beach. Wellman is on the pier above them and looking through a telescope at them. Yet, when the producers try to give the viewer the sense of looking through the telescope, the camera is actually down on the beach, level with Bosley and Ellen. BTW, looking through a telescope and trying to fire a gun at the same time is a questionable technique.
When Wellman is on the phone, he writes down Bosley's license plate number. Later, when he arrives at the restaurant, he spots Bosley's car and checks to see if the plate matches what he wrote down. In a very tight close up of Bosley's car, the plate number matches. Every other time in this episode that you can see either the front or rear plates on Bosley's car, the plate number is not the same one shown on the close up that was used when Wellman checks it.
When Bosley leaves the office to rejoin his new friend back at the restaurant he is shown getting into his car parked out on the street. The sound of his car starting is heard but Bosley never turns the ignition to start it. It must have already been running since he gets in and immediately puts the car in gear and drives away.
After talking with the Angels and making his "bet" with them, Bosley walks out to his dark-green Thunderbird and gets in. He puts the car in gear without even turning on the ignition. Yet, sound effects are used as if he did indeed start the car.