In the movie, security for the illegal medical experiments is provided by two supposed police officers named Hare and Burke. In reality, William Hare and William Burke were two men in the business of supplying human cadavers to medical schools in 1820s Edinburgh - until it was learned that the ones they hadn't stolen from graveyards, they had murdered themselves.
If, after Guy gets shot and then conked on the head in Jodie's apartment, he indeed was found in a coma five days later, his beard would be much fuller. The movie never depicts that stage though and they would have shaved a coma patient.
Guy is told he severed his spine at C6 and was paralyzed from the neck down. In reality an injury to the C6 vertebrae would result in paralysis from the chest down - meaning he'd still be able to move his arms (although finger function would be impaired). However with regards to injuries to C6, or any level for that matter, what is more important is level of nerve damage to determine amount/location of paralysis.
Dr. Lawrence Myrick: People die everyday. And for what? For nothing. What do we do? What do *you* do? You take care of the ones you think you can save. Good doctors do the correct thing. Great doctors have the guts to do the right thing. Your father had those guts.