Shortly after the intro, when Jefords is talking with Peralta about whether or not he went to the hospital, Jefords says "Your tone is braggy but your words are real sad." Behind him, you can see an Asian female cop walking with a perp walk onto the screen towards Jefords. Two lines of dialogue later, when Jefords asks if the hospital cleared Peralta for active duty, the same Asian female cop and the same perp walk onto the screen in the exact same direction.
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.
Jake laughs off a doctor's diagnosis of his internal bleeding, stating that, "That's where the blood's supposed to be." In Unsolvable (2014) a year earlier, Jake discussed a convict's injuries following a jailhouse beat down, including internal bleeding, and was fully aware of what that meant.