Continuity mistake: After the mystery is solved, the gang are driving away in the Mystery Machine. Shaggy and Scooby are in the back marveling at their wax dummies. Velma, Daphne, and Fred are in the front seat and can look back at them. But when it shows an angle from in front of them, the inside of the van behind Fred, Daphne and Velma can't be seen, only a solid gray wall where you should see Scooby, Shaggy, and their dummies, and even the back doors of the van.
Continuity mistake: Fred begins telling the gang his plan for trapping the Wax Phantom. They are standing at a window with Fred on the right, Daphne in the middle, and Velma on the left with Shaggy behind them. It cuts to a view from behind, and suddenly Daphne and Velma have switched spots, and Shaggy is off to the side.
Continuity mistake: In Mr. Grisby's house, Shaggy says "what a place to live," and Mr. Grisby is shown to be on the left side of him, Scooby and Velma with the crystal ball on their left. It cuts to a different angle as Velma says "it's a nice place" and Mr. Grisby is suddenly on the same side as the crystal ball with his hand on it.
Continuity mistake: Fred is explaining his plan to check out the wax museum and Daphne is standing beside him. In the far shot she is facing him with her hand on her hip. It cuts to a close up of Fred and suddenly she is facing the same direction as him and has her arm down at her side.
Continuity mistake: Shaggy and Scooby stop to play a game of pool. When Scooby looks up and notices the ape head trophy has vanished, he has 4 of the balls by him, including the 6 ball. It cuts over to Shaggy, and he has the exact same set of balls next to him.
Continuity mistake: The Ape Man puts on a mask of Scooby and pretends to be a reflection. As he is mimicking Scooby's movements, he places his hand to Scooby's and his nails are sticking up. It cuts to a different angle and his hand is in a slightly different position, and his nails vanish.
Continuity mistake: Scooby finds a half eaten hamburger in a plate on the floor. When the camera cuts further back to show Shaggy, the plate has moved on the floor, as noted by the lines between boards and the placement of the plate and the spider web on the wall.
Continuity mistake: When Shaggy makes the joke about living without a smart Ape Man, he's lying on his stomach with his legs in the air behind him. His feet are apart as he relaxes. Then suddenly in the same shot, they just jump close together and then slowly spread back apart.
Continuity mistake: After Candy and the stunt man quit the movie, Mr. Maxwell says he has to withdraw his job offer to the gang as it's too dangerous. As the gang is shown, Scooby is sitting in front of Shaggy and Fred. It cuts to a close up of him as he gets excited about this, and suddenly Fred and Shaggy have vanished.
Continuity mistake: The Ape Man breaks the rope bridge that Scooby is on and it begins to fall. But by the Ape Man, the stakes holding the broken ropes are still in the ground at his feet. Scooby falls down and lands on a root, which bounces him back up where he punches the Ape Man. The stakes and broken rope have vanished.
Continuity mistake: The camera pans over the filming set and stops on the gang with Mr. Maxwell. There is a van behind them with the Ape Man movie poster on the side. The vinyl piece on the side of the van goes behind the poster and is lined up directly with the orange letters saying "EPI-CENTER FILM COMPANY." It then cuts to a close up of the poster and suddenly it has moved up on the vinyl and become smaller, lined up with the underside of "LOCATION No.2"
Continuity mistake: When Fred is reading his book in bed, he is wearing his pyjamas, but when Fred says "You got to be kidding", he is wearing his regular clothes, and when he, Scooby and Shaggy go back into the bathroom to inspect the bathtub, Fred is back in his pyjamas again.
Continuity mistake: In a full view of the Scooby and the gang in the Sheriff's office at the end of the episode, Velma is sitting on a chair and you can see there is nothing beside her, but after a quick cut of the Sheriff, we return to Velma and Shaggy and a filing cabinet has suddenly appeared.
Continuity mistake: In a shot of Fred, Daphne and Velma in the Mystery Machine, Fred announces that they are at Beach Boulevard and you can see that Velma has nothing on her head. But after a quick cut to the radar, we return to Velma and she is now wearing her earphones.
Continuity mistake: When the Mystery Machine is driving down Beach Boulevard, you can see Fred and Daphne are sitting in the front seat. When Velma locates Scooby-Doo on the radar using the transmitter in his collar, we cut to the Mystery Machine and Fred and Daphne have now gone.
Continuity mistake: When the gang are in the Malt Shop at the end of the episode, Scooby puts straws together to steal Shaggy's drink, and succeeds until Shaggy cuts the straw. But after Velma says "That closes the mystery!", Scooby starts drinking through his straw and we cut to the other four drinks on the table. This time, Shaggy's glass is completely full.
Continuity mistake: When Daphne suggests leaving the painting room through another door, the Black Knight appears and you can see he has red crest of hair on his helmet. But after a quick cut, we return to the gang and the crest on his helmet is missing. It re-appears when he comes to the painting that Shaggy is hiding behind.
Continuity mistake: When Scooby Doo and the gang are pursued by the invisible ghost with a candle, they hide in a room and Scooby blows out the candle and shuts the door. You can see the door has a handle on the left hand side, but when we see the gang in the room in the next shot, there is no handle on the door.
Continuity mistake: When Velma loses her glasses, the Black Knight trips over her and lands on the guillotine. She mistakes the Black Knight's growls for Shaggy's sore throat, and pours some cough mixture on to a spoon. When Shaggy enters and runs up to Velma, she is wearing her glasses again.
Continuity mistake: Daphne is wearing pink tights at the start of the episode, but when the gang discover that the safe was robbed after freeing Johnny Sands, look at Daphne and you can see her tights are missing. They reappear when we see her with the gang a little later on.
Continuity mistake: Right after the car chase when the Mystery Machine crashes into the boat and fishes, when Scooby reaches into the pile of fishes, his arm turns green. When he pulls out the fish, his arm is back to normal. But when he reaches back down it changes to green then back to normal when he pulls out Shaggy.