The scene where the Arrow, after suffering an injury from a duel with the Dark Archer, jumps out of a window and calls Diggle for help is quite similar to the scene in Batman Begins (2005) where Batman, after being set on fire by the Scarecrow, jumps out the window and calls Alfred for help.
"Corner of O'Neil and Adams" as mentioned by detective Lance comes from two names - Neal Adams and Dennis O'Neil, famous comic-book artist and writer respectively. Both have contributed a lot over the years to the world of DC and Green Arrow in particular.
The Last Scene in this Episode has some similarities to the Smallville's Lexmas (S5 E9) episode as they both are not only Christmas Episodes of their respective seasons. But also both they both have a Main Character of their respective shows Ending Up In A Hospital Room at the End of The Episode, and Both having the said characters Looking Out The Window with a Renewed Determined Thoughts. While the Camera is Zooming Out Through The Hospital Window that each said character is starring out of before Blacking Out towards the End Credits. And In Both Shows the For Mentioned Scene take place on a Cold Winter's Night and in addition Both where the Ninth Episodes of their Respective Shows.