Other mistake: After being shot in the air traffic controller's office, the alien disintegrates, but the black residue remaining afterwards is out of position from where the alien disintegrated.
The Leeches - S1-E4
Other mistake: David Vincent arrives at the airport and a sign says "Welcome to San Diego", but the episode takes place in Arizona and references Arizona-related locales: Tucson, Maricopa County, etc.
Continuity mistake: The dead air traffic controller's body changes position from being splayed out on his desk to sitting upright in his chair when the scenes instantly cut.
Other mistake: The Invaders' computer announces David Vincent has "sandy" hair, but Vincent's driver's license states he has brown hair. His license also says he has brown eyes, but the actor playing him has blue eyes, and the computer says he's 5' 11", even though one of the Invaders entered the 5' 9" info from his license into the computer.
Continuity mistake: The bartender behind Doctor Raynerd changes positions as the camera shots quickly change angles.
Other mistake: The sheriff drives a hard top, solid roof police car yet he wears a motorcycle cop's helmet.
Visible crew/equipment: Light reflecting screens are seen in the rear doors of the Midlands Academy van.
The Spores - S2-E7
Plot hole: Hal and Roy could not open the spore case with an electric power drill, but later a married couple pops it open with a hammer and chisel, then much later some children acquire the case and easily open it.
Continuity mistake: Like most episodic television shows, the facial and bodily injuries David Vincent acquires (bullet wounds, knife wounds, etc.) in an episode are not carried over into subsequent episodes.
