"1-Adam-12, 1-Adam-12, please respond to a 10-101 ... sighting of tropes seen in this episode":
Blackmail: Malloy realizes, after questioning a woman Officer Johnson hoped would help clear his name, that Johnson is indeed blackmailing witnesses to keep quiet, and is pissed off. When Johnson reminds him he saved his life a few days earlier (stopping a runaway a forklift that was about to run down Malloy, this while apprehending robbery suspects), Malloy is even angrier.
Broken Pedestal: Johnson's actions earlier in the episode, where he stopped a runaway forklift from running over Malloy, were noble, but he tries to use the incident against Malloy when his criminal activities are found out.
Clear Their Name: Johnson confides in Malloy that he is under investigation – "unfairly," he says – for blackmailing witnesses and suspects, says that a witness named Ginger can clear up matters and asks Malloy and Reed to locate her. Malloy . asks Malloy and Reed to locate a witness to prove Johnson isn't guilty of these crimes. Malloy gives Johnson the benefit of the doubt ... until he questions Ginger and her story proves to be a bit too matching to be true.
Dirty Cop: Officer Tony Johnson, one of Malloy's closest friends and confidants on the force, turns out to be one of these.
Ungrateful Bastard: What Johnson paints Malloy as after Malloy refuses to back down in telling him he will make sure he (Johnson) is criminally charged with blackmail and removed from the force.
You Owe Me: Just like Ungrateful Bastard, with Johnson throwing the series of events back at him, and tells him that the right thing to have done is just let everything with blackmailing witnesses slide and they'll be OK. Malloy just gets more pissed.
