Continuity mistake: Scooby finds a clump of ape hair stuck in the wine cask. It cuts to the gang, then back to the cask as they walk up and suddenly the clump of hair is twice as thick. (00:16:45)

Don't Fool With a Phantom - S2-E8
Continuity mistake: The gang find Jonny tied up in a chair and he says it wasn't a publicity stunt. Both his arms are tied up to his sides by the rope. It cuts from the close up to show them all again, and suddenly Jonny is holding his hand to his head and Fred is suddenly pulling on the rope, his arm outside of the rope. (00:02:45)
Continuity mistake: When the gang 1st arrives at the beach. Fred stops the Mystery Machine. Although the van is stopped. The next shot shows Fred still sitting at the wheel, turning it, as if he is steering.
Continuity mistake: Just before Shaggy goes into the secret passage way, he sits on a stone, and his hair has somehow turned yellow.

Don't Fool With a Phantom - S2-E8
Continuity mistake: When the door to Mr. Grisby's house opens, Shaggy and Scooby have their back to it with Shaggy holding Scooby's head. It cuts to a different angle, and instantly Shaggy has let go of Scooby and they are facing the door. (00:05:10)

Continuity mistake: The gang emerge from the secret tunnel and find the movie crew dressing rooms. It shows one, then cuts back to the gang. Then it cuts back and suddenly another dressing room trailer appears next to the one seen moments before. (00:17:20)
Revealing mistake: After Mr. Maxwell says that the local people refuse to work on the movie, Velma asks why. In her close up, her right pupil is horribly misshapen. Not round, but a wobbly, almost cloud like shape. (00:01:35)
Jeepers It's the Creeper - S2-E3
Other mistake: There is a scene where the gang is the home of the Bank President, just after dropping off the injured bank guard. At one point the Bank President is standing behind an end table of some kind with a lamp on it. Even though there is nothing underneath the table to block your view you cannot see the lower part of the Bank President's leg. It looks like it has been cut off.
Plot hole: It's established at the end that Greenway used transparent skis to create the illusion that the Snow Ghost could fly. But there's no way skis could have enabled Greenway to fly over the gorge, especially from a standing position. (00:05:30)

Don't Fool With a Phantom - S2-E8
Revealing mistake: When Fred makes a joke about the dummies at the end of the episode, Daphne doesn't have a neck. (00:20:55)

Don't Fool With a Phantom - S2-E8
Continuity mistake: Velma gets mad and stomps her foot, activating a secret switch. The floor is made of square and rectangular stones. The angle changes to show her Fred and Daphne, and suddenly the stones are of random organic shapes. (00:12:50)
Don't Fool With a Phantom - S2-E8
Other mistake: When the wax phantom appears behind Scooby and Shaggy the man who supposedly is impersonating him in the suit is in clear sight directly behind Fred Daphne and Velma.
Other mistake: When the gang are swimming, a plant in the foreground moves along with them.

Don't Fool With a Phantom - S2-E8
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. (00:20:50)

Don't Fool With a Phantom - S2-E8
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. (00:17:15)

Don't Fool With a Phantom - S2-E8
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. (00:05:30)
Don't Fool With a Phantom - S2-E8
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. (00:04:20)
Revealing mistake: After the Ape Man runs up the stairs, Fred presses the button to turn the stairs into a slide. But you can see as he moves his finger to the button, he never touches it. His finger hits the switch above the button. (00:19:25)

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. (00:14:50)

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. (00:07:20)
Chosen answer: A ghost wouldn't have to keep any food in the fridge - they don't need to eat. So it is one thing that proves the ghost is not a ghost.