Semi-automatic pistols do not go "click"
I was watching an episode on DVD where Provenza was at the range trying to requalify with his service pistol. He fired at his target and when the ammunition ran out, his pistol went "click" and the slide stayed forward. There is no "click." On semi-autos the hammer remains cocked and the slide stays to the rear, ready to accept a fresh magazine.
"Castle" made the same mistake over and over.