Sherlock suggests to Captain Gregson that he marry his girlfriend so she can be on his health insurance. He says it should happen soon because open enrollment is about to end. Getting married is a life event that would allow her to enroll outside of open enrollment, so open enrollment ending would have no relevance to the timing of the wedding.
When Sherlock and Joan are first interviewing the manager of the retreat, an extra appears behind Sherlock clearly using a metal detector back to front. He then disappears in the next shot and is not seen again.
When Holmes and Watson are reviewing camera footage back in their apartment. Holmes says, all we have is a face in the crowd and a 30-year-old snippet of film.
He should have said, a 30 second snippet of film.
He should have said, a 30 second snippet of film.