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 finds a box of Popsicles in Holt's freezer (which he then puts down his own pants). Captain Holt and his husband famously abhor processed, sugary treats. Although it's possible that Amy bought them for their quarantine.
During the case Jake and Holt get mumps. Amy says she has been immunized against it, but it seems out of character for Holt not to have gotten an MMR shot or booster.