At the end of the car chase, after the white pickup truck smashes into the left side of Joe's car, the truck is not seen in the subsequent scene which shows a tow truck smashing into the back of Joe's car immediately after the white pickup truck hits his car. Since the camera is on the tow truck's right, when the tow truck is shown approaching and hitting Joe's car, the white pickup truck should have been seen to the left of the tow truck driving away from Joe' car, but it's not seen anywhere. It's also not seen in an immediate subsequent shot of the area behind Joe's car.
At the beginning of the car chase, when Joe's car takes off from the curb, the right rear tire has a hubcap on it. In the next shot, the hubcap is missing from the same tire. Then in the very next shot, when the car turns right and heads up the hill, the right rear tire has a hubcap on it once again.
When Joe and his client are talking to the police chief in the police chief's office, a mysterious shadow of what appears to be either a crew member or a police officer appears on the wall behind Joe. It shows a person with a hat on suddenly standing up and walking to the right, but based on the initial wide shot of the room, there's no one else in the room besides Joe, his client, and the police chief, all three of whom are stationary throughout the scene and none of whom have hats on.
34 minutes in, with Nancy Kovack "Barbara" in his office, when Peggy takes leave of Mannix he gets her name wrong when he says "Thanks, Maggie" to her.