Jake and Amy's wedding anniversary is in May and so should take place after this episode, but they celebrated it much earlier in the season in the episode "Casecation".
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.
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.
Terry reveals that he actually took the lieutenant's exam weeks earlier and passed, and therefore he already held the rank of lieutenant without anyone knowing. As Terry's precinct captain, Holt would have been informed via official channels that one of his subordinates had earned a promotion in rank.
Jake and Charles are unable to lift Terry when he is concussed. Charles was able to lift Terry by himself in DFW (2018).
Being such a staunch grammar champion, it's hard to believe that Captain Holt would use the word 'snuck' instead of 'sneaked' when describing how he took the belt during the previous Halloween heist.
After Terry wins the heist, Holt declares him to be, "an amazing human being/genius." The correct phrasing, as inscribed on the previous years' plaques and belt (cummerbund), is "amazing human/genius."
When attempting to remove the medical alert bracelet from Earl ("fake Scully"), Holt orders Amy to wrap her legs around him to anchor herself. Amy instead braces her feet on Earl's chair.
Upon learning that Cheddar assisted Terry in obtaining the bracelet, Holt refers to Cheddar as a "duplicitous bitch." A bitch is a female dog. Cheddar is male.