Jake's fish hook necklace flips orientation between between shots.
When Peralta goes into Holt's office Holt's pen switches locations and briefly disappears before reappearing on his desk.
Scully says he doesn't get the internet on his phone, which is a "Netscape Blip." While that is a fictional phone, Netscape was a computer services company best known for developing a popular, eponymous internet browser. It later merged with AOL. Such a company would not make a phone that is not internet-capable.
Santiago is wearing 2 citation bars that are not issued by the NYPD. Also, NYPD regulations require that the American Flag bar be worn as the highest citation bar - something Santiago would have known.
Captain Holt wears his Commendation breast bar above his World Trade Center Breast Bar. When the WTC bar is worn, it is worn above all other medals, but below the American Flag bar.
There is no way Jake could have taken a picture of Holt in his red bowler hat at the angle at which he was holding his phone.
The 4th floor women's bathroom has been seen before and the layout was nothing like it is seen here. It previously contained multiple stalls, whereas here there is a single toilet with no stall walls around it.
While discussing finding a bra in the backseat of his father's car in third grade, Jake says, "maybe it flew in on accident." The correct phrase is "by accident."
Hitchcock and Scully balk at the idea of them possibly getting in a fight. They have been in multiple fights, for example, over a sandwich or because Scully was spending more time with his new girlfriend.
Jake says that doctors suggest drinking 8 glasses of water a month, which Terry corrects to "a day." Jake tells him this is no time for jokes. Jake drank 8 glasses of water a day, at Amy's insistence, in The Slaughterhouse (2017).
Jake states that Holt doesn't like pizza, but offers him a slice anyway so that he can feel more welcome while commiserating with the rest of the squad. In Sal's Pizza (2013), Holt was revealed to be subscribed to Charles' pizzeria-rating email blast, as it was more informative than other pizzeria-rating email blasts (being the only one that measures mouth feel). That would not make sense if Holt didn't like pizza.
Gina has been working for the police for years at this point and would not have needed to ask what "show me going" meant, she would have known already.
When Holt demands to know why Hitchcock and Scully are fighting, Hitchcock says that Scully punched him in the nuts, so he punched Scully in the nuts, etc. Hitchcock was shown throwing the first punch, not Scully, but no one corrects Hitchcock's account of the events, not even Scully.