When Rosa and Jake pass one another while walking on desks, Jake is heading away from his desk, towards the kitchen, yet ends up at his desk.
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.
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.
In one of the early episodes Jake says that Hitchcock went bald at the age of 15 but in a flashback scene of Hitchcock and Scully, you can see a young adult Hitchcock having great smooth hair.