After the drone attack, Beckett puts her gun back in the holster. Then, in the next shot, she starts the movement again. Then her arms are at her side, then once again she is putting the gun back.
When Beckett is asking Omar out in the park, the man following them raises his arm and puts it in his jacket to pull out his gun. In the next shot, his arms are down again.
It is stated that the information on the USB drive was downloaded to a 4 gig hard drive. It is impossible to determine whether information has been copied off a USB drive let alone exactly what kind of device it was copied to.
When Stack is answering his phone, you can see the iPhone menu. When you have a phone call on an iPhone, the screen turns off thanks to a sensor next to the speaker so that you don't accidentally hang up by nudging the touch-screen with the side of your face. If there was a real call, the screen would be black.
If the federal government including the attorney general's office is involved in a case, the New York Police department would be told from high up that they have no jurisdiction and cannot be involved. And the attorney general's office would have been calling Beckett's supervisor not her directly.
After the drone is shot down in the field and Castle claims credit, Beckett comments on Castle's terrible shooting, but in an episode in an earlier season, he demonstrated amazing marksmanship when he was at a gun range with Beckett, by rapidly firing four shots within the smallest circle on the target.
He also showed his shooting skill in another episode when he and Beckett fired towards each other to hit criminals standing behind each of them.
He also showed his shooting skill in another episode when he and Beckett fired towards each other to hit criminals standing behind each of them.