“In the words of a good friend: Bite me.”
Important. Also, Edlund wrote this episode and “The Third Man”, so it’s likely not a coincidence.
I actually kind of like that he would mention Balthazar. He inspired Balthazar to rebel. And Cas went crazy/paranoid and killed him. He was like this frivolous pleasure seeking side of rebellion, or disobedience and Cas when he became God literally killed that pleasure seeking rebel part of his life. Cutting himself off from the emotions or whatever. But Idk, to show that Cas is working through his guilt over what he did enough to fondly refer to the good times that he and Balthazar shared and referring to him as “a good friend” it shows that he’s growing and working through his issues.
And yeah it could also be Dean, he has said bite me in front of him. Also i find it funny that he’s responding in response to “where’s the tablet” -hint it’s inside him- and when Dean says “bite me” the ash that will kill Eve is inside him. So if it is Dean it’s also a little hint hint nudge nudge foreshadowing to where he is actually keeping the tablet.