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.
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).