Factual error: At one point in the film there is footage on the news of Mystery Inc's embarrassing attempt to stop the ghouls from stealing costumes. In particular, it focuses on Shaggy and Scooby being dragged across the table, etc. But look at the angle it's taken from: no one could have taken that.
Visible crew/equipment: When Fred and Daphne are held by the Tar Monster, you can see a crew member hiding in the background.
Continuity mistake: C.l Magnus takes the cigarette out of his mouth three times.
Answer: The jumper cables "conducted" the 10,000 Volt Ghost into the Black Knight, causing them both to explode.
Sierra1 ★