One of the robbers uses the name Trapper John.
Ian Kahn's character 'Sal' shares the same first name with John Cazale's character. Both the episode and the movie are about a bank robbery.
Robber addressed as "Dr. Huxtable"
Castle says his plan worked in this movie
Robber addressed as "Dr. Howser"
Robber addressed as "Dr. Quinn"
Towards the end of the episode, an officer hands lead negotiator Captain Peterson the phone, saying it is "Sgt. Roman." This references Samuel L. Jackson's character Danny Roman, protagonist of "The Negotiator (1998)"
Castle suggests "Dr. Phil" as a better TV doctor alias
Castle suggests "Dr. House" as a better TV doctor alias
Castle suggests Dr. Howser could have used a better name, such as Dr. Shepherd.
Castle says he "had to brave the hellish flames to pull [Beckett] out of [her] bathtub"