The amazing Tatort episode "Im Schmerz geboren" didn't run short of references to classic Shakepearean tragedies, diegetically as well as structurally, but one of them eluded me and I don't know if there is more to it than my limited knowledge of Shakespeare's works allows me to recognize.
After Richard Harloff did his "magic" with Don Bosco and secures his henchmen's loyalty, they apparently talk about Shakespeare's The Tempest:
Harloff: You're leading hand here? What do you think about the situation?
Caliban: Don Bosco was okay. But who wants to survive can't afford the loyalty to a dead man.
Harloff: Generally I would disagree with you, but in this case not.
Caliban: With respect, should the cops come here, it would maybe be better if he'd already be on his way to his "estate" in South America.
Harloff: Haha, thought quickly...How's your name my son?
Caliban: Bosco either called me Ariel or Caliban, according to his mood.
Harloff: Haha, Bosco and his Shakespeare, but I like it. I'll call you Caliban, for an Ariel I already have.
After that the camera pans to Harloff's (or actually Murot's, as we find out later) son David, who shot Don Bosco with a sniper rifle.
I wonder if this naming choice offers some more insights into the characters and their roles and relationships beyond just being part of Don Bosco's infatuation with Shakespeare. Now in-universe there are only two choices for Harloff to make, but he seems rather confident that David is the Ariel and not the Caliban. But out-of-universe there are actually even more choices, since Bosco's pick of The Tempest doesn't come out of nothing either. So what makes David more of an Ariel than a Caliban? Does it maybe even already foreshadow Harloff's true feelings for his son? Or does it also tell us something about "Caliban"'s (the movie character) fate or his relation to David in the story?