Deputy Commissioner 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.
Deputy Chief Ed Williams is not wearing his American Flag commendation bar as his highest bar as required by New York Police Department regulations. Also, most of the commendation bars he wears are "fake" and not issued by the NYPD.
The tie that Jake plans to gift to Holt, purported to be the first tie he ever got when Holt started making him wear them, is not the same as the tie(s) he wore in the pilot. It is dark blue with thin, light-colored lines in a diagonal pattern. The two ties he wore in the pilot were a brown tie with thick, light blue stripes (tied around his mid-section) and a dark blue tie with light-colored diagonal triple-stripes.
Holt's insignia is very messed up. In Renewal (2021) it was stated that Holt would be promoted to Deputy Commissioner, which is indicated by the 3 stars he now wears. However, his new badge has 2 stars on it with the title of "Deputy Chief" (which is only a 1-star rank). The prop and costume department appear to be very confused on this show.
Amy is mad that Jake "cheated on her" with another notary, but notaries are not allowed to notarize documents signed by their spouses. As Jake says he put thumb prints in the log book, it means he signed Terry's letter, too, making it impossible for Amy to serve as the notary.
When Jake and Amy are discussing whether the squad has ever been to the Brooklyn Bridge together, there is a cutaway to the final shot of the opening credits sequence, with the squad walking in slo-mo with a bridge in the background. It is the Williamsburg Bridge, not the Brooklyn Bridge.
When Captain Holt reveals his tattoo, Rosa is equally shocked as everybody else, when she shouldn't be, since she already saw his tattoo ("Blue Flu").
Holt's tattoo is revealed to be a tramp stamp of Cheddar with Kevin's head. Members of the squad saw Holt without a shirt on in Beach House (2015) (the entire squad), Coral Palms, Part 2 (2016) (Jake), and Honeymoon (2019) (Jake and Amy) and there was no tramp stamp. The last two incidents were around or after the time when Holt admitted to having a tattoo (without revealing what it was), so the tattoo would definitely have already been present.
Holt reveals that his tattoo is a picture of his dog, Cheddar, with the head of his husband, Kevin. The image of Kevin has a beard. The existence of Holt's tattoo was first revealed in Coral Palms, Part 2 (2016), at the beginning of season 4, but Kevin did not grow a beard until season 5. He was clean-shaven in all earlier appearances, including flashbacks.
Pimento plans to stop a pack of wolves that has been terrorizing a Canadian diamond mine by killing the alpha and taking control of the pack. Wolves do not have an "alpha." The notion of an alpha wolf was based on misinterpreted data from a single study of one wolf pack that has long since been discredited. Even the study's author has disavowed its findings.
When Holt reveals himself in Jake and Amy's shower, he announces himself as "Captain Holt." He is already wearing the 3-star rank insignia of a deputy commissioner, not his old captain's bars, indicating he has already been promoted and is no longer Captain Holt, but Deputy Commissioner Holt.
Jake states that Terry has the same physique and personality as the Kool-Aid Man. the Kool-Aid Man's body is almost a perfect sphere, while Terry has a trim, muscular physique and is often described as triangular in shape.
Jake refers to "Captain Holt," but Holt has now been promoted to Deputy Commissioner.