Factual error: When Mac is held hostage until he can prove that the bank robber did not shoot the manager, he asks for a portable CT machine to be delivered. CT stands for computed tomography which is a machine that takes slice pictures of the body and puts them together to form a whole image. This is why a CT machine has a tube like quality to it, so it can take slice-like pictures around the body. When it arrives the machine is not a CT at all, but an ultrasound. This is made obvious when Mac uses the transducer probe (wand-like attachment) to scan the body. Anyone who has had any of these procedures done, or has seen them in TV shows, or knows how to search images on the internet can see the difference between these two very different machines.
Factual error: "The Thing About Heroes" When Mac has a flashback to an incident when he was 14 years old (in the 1970s) and gives the money to Bobby Toole the twenty-dollar bills all have the large 20 on the back side. This was not issued until 2004.