Batman: The Long Halloween Animated Film Voice Actors Cast!

[Frontier]

Maybe I missed it, what was the end credit scene?

Green Arrow and Flash show up at Wayne Manor.

Batman always has his own code.
Letting her go at the end didn't seem that big of a shock.
Batman's sense of justice, doesn't always align with that of the police.
After all, Batman is a vigilante.

I think with his sense of justice and guilt over Alberto's death he'd feel almost compelled to at least do something.

[RobinGA]

Obviously not, since he let her go.
Just wanted a promise she wouldn't do it again.

I'll admit that if it were me that isn't the choice that I would make.
Nor should it have been the correct course with someone who had murdered people.
But I can see how Batman would reach a different conclusion.
He doesn't kill, but sometimes reaches a conclusion that it is hard to accept ethically.

[Frontier]

Obviously not, since he let her go.
Just wanted a promise she wouldn't do it again.

I'll admit that if it were me that isn't the choice that I would make.
Nor should it have been the correct course with someone who had murdered people.
But I can see how Batman would reach a different conclusion.
He doesn't kill, but sometimes reaches a conclusion that it is hard to accept ethically.

Which, to me, didn't really fit his development in the movie. But that's just me.