It Crawled Out of the Woodwork - S1-E11
Factual error: When the energy monster kills his entire research staff by stopping their hearts, Dr. Block brings them all back to life (with their minds and personalities intact) by installing pacemakers. But when the heart stops functioning, brain death occurs within minutes. For this to work, he'd not only have to operate on several people simultaneously, he'd also have to be the fastest heart surgeon on Earth. (00:40:00)
Factual error: The General brandishes a six-shooter pistol with an enormous silencer attached to it. He's a career military guy who should definitely know better, so he gets a failing grade in Basic Weaponry 101. Silencers don't work on revolvers. (00:34:50)