I think everyone has seen the variation where Danny kills Joker and Jason (and maybe other bats?) sees his panic and then congratulates him
But what if his panic was stronger? He's never killed before. All but a couple of his enemies were dead before they fought him. Or at least half dead But that clown? Oh my god, he was alive. Yes, he smelled like ecto (which only added to the freak show vibe and the panic reaction) but he was alive And Danny killed him
Danny's panic about his first kill, about meeting a crazy clown, about his screw up version that killed
And the fact that that hot guy in the domino mask (wasn't he wearing a full red one?) is laughing doesn't help at all Oh, here come the police. Are they going to arrest him?
with the bats just appearing there and distracting the police he can almost feel a small relief from the realization that the clown is evil interrupted by terror from the memories of their discussions with Sam and Tucker that Batman is very obsessed with his clown and does not allow anyone to kill him and what does this mean for Danny now?
Eventually Jason will turn his attention to his hero and notice that he does not look proud. Or at least somehow good. He looks like he is now choosing whether to faint from horror or puke from the blood on his shoes pouring from the clown's head, from which the guy can not take his eyes off and- oh The calmed rage of the pit rises to protect who made him afraid who made him cry!? Well, it looks like Jason will have to be a hero to his hero. And it needs to happen now. No, the police and B can wait. Get lost.
