While speaking with Rosa, Amy asks her desk mate from the (temporarily displaced) 9-8 to put his service dog on a leash, to which he balks. The dog was seen on a leash just a few scenes earlier when first introduced.
During Jake and Stevie's flashback to their glory days, the NYPD patrol car shown has a New York state license plate on the front. However, NYPD marked cars do not have license plates; they have a placard with the unit number instead.
During the fight between the two precincts, when Captain Holt calls out everybody you can see that the 98's Captain is under the door. At the next shot he is clearly coming from the desk chair.
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.
Most of the commendation bars Deputy Inspector Flynt wears are not issued by the NYPD.
[Incorrectly added as a goof] When explaining to Gina why he can't kick Captain Flynt out of his office, Captain Holt says that Flynt is his superior officer. He and Flynt are of equal rank and position (precinct captain). Flynt is actually a Deputy Inspector (major) and is one rank higher than Holt.
When Jake is telling Charles that he can have as many close friends as he wants, he mentions that he might look up his friend James from college. It has been established that Jake did not attend college. He enrolled in the police academy out of high school.
Terry states that, because all the materials that the 9-8 brought into the bullpen are blocking the windows, they can start a new office on the roof. Captain Flynt of the 9-8 is using Holt's office, which still has an unobstructed view of the rooftop. Terry and the others should realize that their entire plan would come undone if Flynt were to happen to take one glance out of the window.
When Gina informs Captain Holt that the captain of the 9-8 is adjusting his chair, Holt asks, "Even the lumbar," to which Gina replies, "Exclusively the lumbar." The captain of the 9-8 is clearly seen adjusting the chair's height.
When Jake, Charles, and Stevie burst into the Thirsty Ox, they instruct all present to "show [them] your hands." Ozerov, the suspect they were after, instead puts his hands behind his head.
Jake tells Stevie that Boyle needs to hike up his pants because they don't sell any pants short enough for Boyle. That makes no sense because you can have pants shortened. In fact it would be totally in character for Boyle to personally shorten them himself.