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.
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.
When he has a health scare, Charles says he has to tell his son he'll be an orphan again. Nikolaj was not an orphan. His mother gave him up and his biological father, Gintars, was featured in season 6's Gintars (2019).
Jake states that Aquaman's weapon was referred to as a trident in both the theatrical and Snyder cut, meaning he is referencing the Justice League movie. Aquaman's weapon was not named in Justice League (2017)'s theatrical cut, but it was named once in Zack Snyder's Justice League (2021) and repeatedly in the Aquaman (2018) movie.
Rosa tells Holt she has surveillance photos of McCaffery entering a pet store and buying a mouse an hour before he found it in his burrito, but the photo she shows Holt is of McCaffery leaving the pet store with the mouse, not entering.