Goof (continuity error): Whenever there is an insert of either the radio, the "hot sheet" (list of stolen cars), or when Reed is jotting down information on the pad, the visuals almost never match the continuity of the scene. Example: It can be daytime in the scene, but when the insert of the radio or the hot sheet is shown, they appear, due to the lighting, that the inserts are from nighttime. Also, the same insert of Reed writing on the pad is used whenever he writes info down. As with the errors with the radio not matching the scene, there are times when Reed is wearing the short-sleeve uniform, yet when he's writing info down, we see the cuff of a long-sleeve shirt.
Goof (plot holes): At the opening of every episode, the radio announcer makes a call to Adam-12 and reports some crime in progress. Adam-12 then speeds to the scene - without the benefit of the address.
Goof (revealing mistake): In all episodes throughout the series, during any interior scenes showing the captain's office, which is depicted as having a door and windows facing the hallway and a wall with a window looking into the adjoining office, there is never any glass in either the doors or windows.
Goof (continuity error): Pepe's last name as spoken is "Hernandez" but is listed in the end credits as "Garcia".
Goof (continuity error): When the stakeout is arranged, Sgt. Miller tells Reed and Malloy that they will be on Tact 9. When Adam-12 is getting into position, Reed switches to Tact 1.
Goof (boom mic visible): (at around 6 mins) The boom mic's shadow is visible on the hood of the car.
Goof (continuity error): When he is photographed by Bowen and Gurney putting Henderson in the backseat of the patrol car, Malloy has his hat on. When Sgt. McDonald later shows Reed the newspaper article of the arrest, Malloy is not wearing his hat in the accompanying photo.
Goof (continuity error): When Malloy and Reed leave the station early in the episode Adam-12 is a 1968 Plymouth, it's a 1969 when they capture the senior member of the burglary crew, and it's a 1968 again when they go back on patrol after the capture.
Goof (continuity error): As Malloy and Reed are starting to approach the burglary suspect the gearshift is in Drive, but in the next shot it's in Neutral.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): In the first scene, Reed radios for "code 7 at Duke's Roundup Cafe". The name painted over the windows is "Duke's Longhorn". The name spoken by Reed later is "Longhorn Cafe".
Goof (crew or equipment visible): During the motorcycle chase scene, right after the squad car has nearly caught up with the motorcycle, they are driving into the setting sun. The shadow of the truck filming them is visible on the road at the bottom of the picture.
Goof (continuity error): When they drill the hole in the safe, you can see the hole go through, then the next scene shows a close-up of the door where you can see the hole is not completed, then they put a hose through the hole in the next scene.
Goof (continuity error): When Reed and Malloy are walking into the lieutenant's office, two other officers enter the hallway, but when the scene cuts to inside the lieutenant's office looking out as Reed and Malloy enter, the two officers never walk by the window.
Goof (miscellaneous): When Reed and Malloy are entering the gym, the sign says, "River's Gym", indicating that the proprietor's name is River when it's actually Rivers. Rivers's sweatshirt is punctuated acceptably as "Rivers' Gym", although "Rivers's Gym" would be more correct.
Goof (incorrectly regarded as a mistake): When Reed and Malloy are changing the tire, although it appears that Reed is turning the lug nuts the "wrong" way to loosen them, many Mopar cars in the 60s/70s had reverse lug nuts on the drivers' side.
Goof (continuity error): When they receive the call of the kidnapping, it is dry and mid-day, but when they arrive at the residence it is early evening and the streets are wet from rain, then after they clear the scene, it is late afternoon and the streets are dry again.
Goof (continuity error): When Malloy borrows the blazer from a pedestrian, he buttons up the jacket. In the next shot as he turns the corner, the blazer is open.
Goof (continuity error): When Malloy and Reed first approach the temple for the first time, Reed is on Malloy's right. In the next shot, Reed is on Malloy's left.
Goof (revealing mistake): When Sergeant Strong tells Malloy and Reed of the two suspects in the parking lot beating, he says that their names are Jack Bennett and Paul Bertino. When Sergeant Strong hands over the mug shots of the two suspects to Malloy and Reed, the name on the one mug shot shown has the man with an entirely different name, Howard Dorcy.
Goof (revealing mistake): When the supposedly naked man starts to get out of the car, you can see that the actor is actually wearing a pair of shorts.
Goof (revealing mistake): When placing the naked drunk into the patrol car, you can see an LAPD motor officer in the background stopping traffic for the filming.
Goof (plot holes): Harold tells Reed and Malloy that a home may have been burglarized. After a preliminary check of the outside of the house, the three are standing in the front yard when the owners drive up. When the owner gets out and approaches them, Malloy steps forward and addresses him with "Mr Marshall?". No explanation is given how Malloy could have known what the owners name were. Harold didn't tell them when they arrived.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): Corporal Miller tells the police that his car was so new it had only eight miles on the speedometer. A car's mileage is recorded by the odometer, not the speedometer.
Goof (boom mic visible): During the scene outside the Fosters' garage, the shadow of the boom can be seen on the ground behind Officer Malloy. Also, the shadow of another piece of equipment (perhaps a light) can be seen on the garage wall in between the officers.
Goof (continuity error): The officers are given an address for a 459 (burglary). When the arrive on the scene, you can see the street number painted on the curb. The curb number is different than the number given by dispatch.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): Malloy says he had been on the department 12 months probation plus 4 years when he trained Reed, for a total of 5 years. In the pilot episode when he met Reed, it showed he had been on 6 years.
Goof (continuity error): During the initial car chase, Reed's hat is off in a close-up shot, then on when the camera cuts back to a distance shot when the squad car is making a turn, then off again when the camera cuts back to a close-up.
Goof (crew or equipment visible): When they park the unit in the alley to go on foot patrol, in the window of the building you can see the reflection of people watching them film the scene.
Goof (continuity error): Many of the exterior scenes were taken on a rainy day, the roads are visibly wet with puddles. The interior shots of Malloy and Reed inside the patrol car were shot on a bright, sunny day on dry roads.
Goof (audio/visual unsynchronized): When Malloy kicks the two guns away, the scraping sounds on the pavement don't match the movements of the guns.