Continuity mistake: During one scene in the fake plane going off, a KAOS thug standing in the background has a shadow that magically moves between shots.
Other mistake: During the scene in the prison cell, the first shot has a hair sticking to the bottom right of the screen the entire time.
Other mistake: In one of the car wash fight scenes, two men accidentally kill one another. According to the angle of one of the guns, you can kill someone without actually hitting them.
Continuity mistake: In one shot, both Max and the guy holding him at gunpoint are covered in soap suds, but the next shot shows that only Max is covered.
Maxwell Smart, Private Eye - S3-E5
Revealing mistake: When Max and Trinka jump into the taxi at the start, the cab is in park position for the entire chase scene.
Maxwell Smart, Private Eye - S3-E5
Continuity mistake: At one point in the chase, the black car goes past a corner too fast and backs up so they can go through the street. When the random guy hails the taxi, the black car is reversing again in the background.
Maxwell Smart, Private Eye - S3-E5
Factual error: A revolver generally only holds six bullets, but 99's gun fires way more without reloading at any point.
Maxwell Smart, Private Eye - S3-E5
Other mistake: At the Alledon Arms shootout scene, an agent sneaks behind Max and Max shoots him dead, but at the angle that Max fired, the bullet would have hit the concrete, not the man.
Witness for the Persecution - S3-E3
Visible crew/equipment: When Doctor Baskum demonstrates the cube of safety, a moving boom mike pole is reflected in the glass of the cube.
Witness for the Persecution - S3-E3
Other mistake: In Max's apartment, the KAOS agents fire bullets everywhere, but nothing in the room sparks, explodes or does anything when hit by bullets.
Suggested correction: Assuming the submitter meant Max (since there is no Ma character in this episode), the agents aren't firing at anything in the room other than the Cube of Safety, which isn't made of a spark-able material nor would it "explode".
Witness for the Persecution - S3-E3
Continuity mistake: In this episode Max claims a fear of lightning. But in many other episodes, he's very close to lightning, and he's fine.
Witness for the Persecution - S3-E3
Visible crew/equipment: Set lights are reflected in Doctor Baskum's glasses when he and Max are talking in the kitchen.
Witness for the Persecution - S3-E3
Audio problem: When Max tries to get across the street, in one of the shots of the KAOS agent in the window, he fires a shot (evidenced by the muzzle flash) that's inaudible.
Audio problem: When the two kittens come out of the bushes, they meow several times, but their mouths don't move at all.
Revealing mistake: Vogel gives the address of Mrs Farris to Smart, but in the close-up shot, the paper has no ink on it. It's blank.
Viva Smart - S3-E2
Revealing mistake: Several times during the prison escape scene, the stone wall visibly wobbles.
Viva Smart - S3-E2
Revealing mistake: When Max is cutting through the wall with his laser pen, the wall is obviously pre-cut. You can see the joins.
Viva Smart - S3-E2
Continuity mistake: When Max cuts the hole in the wall, the shot shows that behind the prison wall is another wall. When the group climb out of the hole, they are in a big deserted area with no sign of a wall.
Revealing mistake: In one shot of the graveyard fight, Max is about to hit Mondebello, but when Max is bringing the shovel towards the camera, he visibly slows it down so it doesn't hit the camera.