After 3XK collects Detective Ryan's gun and Badge he checks the gun's magazine reinserts it then racks the slide to load it. After spending some time talking with Castle 3XK you can hear the gun's slide being racked again. If we assume the gun was loaded from racking the slide the first time there is no need to load the gun again.
After Jerry Tyson knocks out Detective Ryan and takes his gun, he can be seen cocking the hammer. The sound of the hammer cocking is also heard. However, Detective Ryan carries a Glock 17 pistol. There is no external hammer on any Glock 17.
During the second interrogation, Gates says he'll only confess if McCardle is given immunity. Beckett turns toward the next room where Captain Montgomery agrees by nodding. But Montgomery is on the other side of a one-way mirror so Beckett can't see Montgomery.
(at around 18 mins) The monologue by Stana Katic: "You wanted to be king again ... All that's left for you to do is to clear the air of all these murders and be done with it all." She says, "Alls", not "All".