None of the bugs Don sprays actually die, they just fly away. His chemicals must be as ineffectual as he is.
Shaggy can't decide whether to enter the corridor or go back to the hallway. Aren't they the same thing?
Freddy's eyes actually pop right out of his head for a second.
See more glitches from this episode.
Don Adam's business card only reads "Don Exterminator."
The paintings are supposed to be of Lorn Chumley in his famous film roles. Yet some of them are dead ringers for the spooks in A Gaggle of Galloping Ghosts. Did Big Bob Oakley copy his costumes from old movies? Even worse, one of the paintings is of Swampy Pete from The Ghostly Creep from the Deep. I guess he copied old movies, too.
Velma speculates that one of the gang brushed against the light switch, causing the lights to go out. Then Freddy suggests that they search around the room for said switch. If they had brushed against the switch, they would be standing next to it, and wouldn't need to walk around the room looking for it.
Otto claims he warned Shaggy and Scooby not to get separated from the rest, but he really said it to the others after Shag and Scoob were gone. More...
