Continuity mistake: In the scene where the old women are grabbing at Eoin at the front door in one shot the top pane of the window on the left of the door is broken and an arm is coming through it, in another shot the bottom pane is broken and the top one is intact and arm is coming through the bottom pane and in the very next shot the top pane is broken again and the bottom one is intact again. (00:13:05)
Character mistake: When Mac, Stella, and Danny are trying to determine where the fired bullet entered the train car, none of them are wearing rubber gloves. But even though they're not handling any evidence, they're still processing a crime scene. (00:05:00)
Visible crew/equipment: During the scene where Dennis and the Waitress, Mac and Dee successively walk into the back office to talk to Charlie near the beginning of the episode, in some of the shots, you can see outside the office door, and you can see the top of the set has no ceiling, and even see part of a stage-light.
Continuity mistake: When Beckett goes to the bathroom to read Castle's book and Castle peers over the top of the cubical to tell her what page the sex scene is on, she is holding the book with her fingers between the pages dividing the book into 2 sections. These 2 sections switch to 3 and then back to 2 between shots.