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.
Captain Kim wears 2 fake medals that are not issued by the NYPD. Also, she wears her World Trade Center breast bar below the Medal for Valor. 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 deduces that Holt plans to snoop around Captain Kim's house because he is wearing sneakers, which she says he only wears for their intended purpose (sneaking). Holt has been shown to wear sneakers on many occasions, such as while exercising, especially power walking.