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.
At around 02:10, Jake briefly looks directly into the camera as he is telling Charles to back off.
Amy tells Jake that grammar is all about syntax and semantics - it's not, it is the study of syntax and morphology that is the structure of language. Semantics is the study of meaning, She had been complaining of being extremely tired so it could have been another mistake.