Character mistake: Joe called Cruz a Sergeant First Class (E-7), which is a US Army rank. It was established in Season 1 that Cruz is in the US Marine Corps, so she would be a Gunnery Sergeant (E-7). (00:19:48)
Episode #1.1 - S1-E1
Character mistake: Abigail says that Max is very unusual as a university graduate who has joined the police, and it can't possibly have been his first choice of career. In fact, well over one-third of British police recruits have been graduates since long before Max would have joined.