Spoiler Level: High
Wow, and I thought the Wonder Woman one was violent!
This is another case where I was only vaguely aware of the source material. I was aware that Jason Todd was back from the dead in the comics because he was alongside Green Lantern Kyle Rayner and Donna Troy in Countdown to Final Crisis. So I asked some friends how he came back, and the general answer I got was that when Superboy Prime was smashing at the walls of his little pocket universe bubble it was sending ripples through the New Earth universe, which led to several characters being resurrected. Which is a bit convoluted, but hey, it's comic books. And apparently Judd Winick felt the same way, because he crafted this tale to give it a more straight-forward and Batman-centric reason.
I can imagine that for people who read the original comic there was more of a mystery who the Red Hood really was, but any suspense on that part is completely lost here by the need to explain to the general audience just who the heck Jason Todd is in the first place. So the film needs to open with the conclusion to "Death in the Family" where we're shown one of the most shocking moments in Batman history-- the scene where the Joker beats the second Robin to death with a crow bar and then blows him up. Although it wasn't handled quite the way I would have done it, it still comes across as properly shocking and harsh as it needs to be.
After having set up just who Jason Todd was, the suspense that the Red Hood is Jason back from the dead is pretty much a give away right after Batman and Nightwing's first fight with him, and the center of the story becomes the question of how he came back, and are his more severe tactics better than Batman's. It raises a lot of good questions and creates a lot of good character drama between Batman, Nightwing and the Red Hood. Batman is blaming himself for failing Jason, but at the same time we also see the stable, self-confidant man that Dick Grayson has grown into because of Batman.
All in all, this is possibly the darkest Batman film I've ever seen, live action or animated. It may be a bit gratuitous at times, but that helps to convey why Batman has a line he won't cross, and why Jason Todd felt it needed to be crossed. Jason's side may even be a valid argument, but Batman reminds us why it's important to not let the heroes be reduced to the villains' levels. And I for one am glad to see that even one of the DC's darkest heroes has never forgotten the difference.