When Castle escorts Beckett out of her bathroom after the explosion, her forehead appears to be clear of any injury. Moments later, when she is sitting in the ambulance, you can see a gash on her forehead just below the hairline above her left eye.
After Castle shoots the gun from Scott Dunn's hand, he says he was aiming for the head. This comment must have been in jest, even though his facial expressions are hard to read, since in Home Is Where the Heart Stops (season 1, episode 7) Castle demonstrated himself to be an excellent marksman, able to fire three consecutive shots into the middle of a practice target.
Despite what Captain Montgomery and Agent Shaw assert, the FBI does not have jurisdiction over serial killer cases unless they cross state lines or the local police invite the FBI to take over. Since none of the victims were killed in other states and Beckett clearly did not invite Shaw and her team to take over, the FBI has no jurisdiction in this case. The FBI doesn't have jurisdiction until the evidence found suggests there are murders across state lines (Seattle, Washington).
Castle: Wow, that's funny... every Sunday my mom would have me make her an ice pack and a bloody mary.
Martha: Don't listen to him. That only happened twice... tops.
Shaw: Castle, what part of un-ass don't you understand?
Castle: All of it.
Shaw: For future reference, it means get the hell out and don't take anything.
Agent Shaw: Castle. Thank you for your help. You are a valuable asset to Detective Beckett's team.
Castle: Well, it would be great if you would call her and remind her of that from time to time.
Agent Shaw: He cares about you, Kate. You may not see it. You may not be ready to, but he does.
Beckett: Yeah, well, the situation with Castle is ... complicated.
Agent Shaw: Honestly, the thing that impressed me most is that you came in with Castle.
Beckett: You know, some people would call that foolish.
Agent Shaw:You made a tough decision on your feet, used the resources at hand. I'd say that's heroic and somewhat poetic. In the end, Dunn did actually face Nikki Heat. She is after all, part you, part Castle.
Castle: Are you in any pain?
Beckett: Well, not nearly as much as you. It's killing you, isn't it?
Beckett: Having to wait this long to tell me how you banged down the door.
Castle: You want me to start from the beginning?
International Episode Titles:
Czech Republic: Vražda jako předloha (Murder as a Template)
Special 2 Part Episode
"We Aright" by The Genders
Original International Air Dates:
Canada: March 29, 2010 on 'A'
Australia: April 25, 2010 on Channel 7
Slovakia: January 4, 2011 on JOJ
United Kingdom: January 5, 2011 on Alibi
Germany: February 4, 2011 on Kabel Eins
Finland: February 20, 2011 on Nelonen
The Netherlands: February 24, 2011 on SBS 6
Czech Republic: March 30, 2011 on Prima
Allusions to Nathan Fillion's old show Firefly from the episode "The Train Job", in which Captain Reynolds (Nathan Fillion) says, "Nice shot," to which Jayne Cobb replies, "I was aiming for his head..." (after he had shot the enemy in the leg).