When Gavin is shaving himself of his hair, the last thing he shaves is his left eyebrow, but in the next, cut-to scene when he starts looking up into the mirror, the eyebrow is unshaven, and the same for when he starts screaming into the mirror in the next shot.
After the Initial Interview between the accused his solicitor, we then cut to the scene In the car. The guy who says his glasses were knocked off must have been mistaken, as they never get so much as moved during the scuffle.
When they give the list of symptoms for Porphyria they list excessive hair growth. This is incorrect, that is not a symptom of that disease. That is associated with Hypertrichosis. Porphyria is usually associated with vampirism.