The Spy Who Met Himself - S3-E1
Other mistake: Max cuts through bars to escape his prison cell, but when he cuts them, he does the top part of two of them, and then the bottom part of only the left one.
The Spy Who Met Himself - S3-E1
Revealing mistake: Siegfried shoots his two thugs, but neither one has a bullet hole in their jackets when they get shot.
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.
Viva Smart - S3-E2
Factual error: When the soldiers fire their rifles at the start of the episode, there should be smoke or muzzle flash at the end of the barrel, but nothing happens.
Viva Smart - S3-E2
Revealing mistake: The drawers in Max's hotel room have no bottom part in them, but Max passes right between the two drawers when he straightens up, so they have no inside-facing part either.
Viva Smart - S3-E2
Other mistake: The glass of lemonade that the room service drinks is poisoned. The room service says it's for the other room when Max tries to drink it, but if you look closely, Don Adams does drink a bit of the liquid, so he should have died.
Viva Smart - S3-E2
Continuity mistake: At the carnival scene, the shot zooming in on the square shows that the Juggler's balls are blue. In all the other shots, they are white.
Viva Smart - S3-E2
Revealing mistake: The juggler accidentally drops the ball in his act, but if you look at the final part of his performance, he deliberately holds one of the balls in his hands so he can miss the final one.
Viva Smart - S3-E2
Other mistake: At the carnival scene, in one a close-up shots of Max and 99 performing, a female extra in one of the windows waves at the camera.
Witness for the Persecution - S3-E3
Plot hole: In this episode, the villain makes a phone call to KAOS headquarters when he's captured demanding that they kill Max to stop him testifying in court against him. Later, several say that Max is the only witness to the villain's crimes, but the Chief and 99 were in the room when the villain made the call, so they could have been witnesses to "conspiracy to commit murder."
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.
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.