When Jake and Holt are in the van, Jake's fake mustache is straight. When he enters the diner, his mustache curves along his upper lip.
When Jake, Holt, and Gordon are talking in Holt's office, Jake's arms go from being folded to having his hands on his hips to folded again between shots.
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.
Amy says she wishes to be featured as "organizer of the month" in a magazine called "Organizer's Quarterly." A magazine that is published quarterly (every 3 months) would not have a monthly feature.