When Martin adds "1188" to Teller's sequence in the last scene, he appears to forget to add the "6" after "975." Note that he nevertheless (inadvertently?) leaves some space between the "975" and the "1188." In Episode 10, "Tessellations," Jake writes the missing "6" in the empty space.
When Abigail introduces herself to Clea, she refers to Martin as her brother-in-law. Later when Clea tells Martin of Abigail's visit, she SEEMS to say that Abigail is his sister. What she ACTUALLY says is correct: "Martin, it's me, Clea. Your wife's sister, Abigail, is here."
During the video blogs, two people are shown in front of the Boardwalk Hotel in las Vegas. The hotel was demolished in 2006.
When Martin comes across an unconscious diabetic, he is directed (via phone) to administer insulin to the man. This is extremely dangerous; the opposite condition is probably occurring: too much insulin for the sugar in the bloodstream. A more reasonable treatment is glucose tablets or simple sugar candy. Extra insulin would most likely put the patient into a deep coma.