Where is 'that' moment though? Is it when he stops Selena from killing Falcone? I know we have the moment of the Riddler goon saying "I'm vengeance". I get the signficance. But is that where Batman fully realizes it? Is it before then?
This is where I think I'm struggling, but want to see how it tracks for me when I see it again. I think we see that Bruce already has heroic instincts. He has a no-gun rule established already. The way he saves the kid at the funeral.
At no point in the film did I think Batman wouldn't try to save innocent people if he could. The flare moment is a beautiful bit of visual poetry that conveys the idea, so I get it, but I feel like the movie is lacking that real moment of clarity where Bruce is making a conscious decision to transition from vigilante to hero with a bigger purpose. He just tells us via voiceover. It's there, but I think the arc is maybe a bit muddier than I would've liked.
This is something that I think both TDK and TDKR handle really well. There are clear moments where a pivotal choice is made that rounds out the character journey. Batman chooses to take the fall for Dent. Bruce chooses to make the climb without a rope and embrace fear again. They're just really big moments that you really feel, that clearly demonstrate the character transitioning-- either his purpose as Batman, or emotionally as Bruce. I understood Batman to be acting in character with the Batman I know here in the 3rd act, but that was inferred more from my outside knowledge of the character vs. something that I felt was clearly earned in this story.
That's just my initial impression though. I'm really hoping a second viewing irons this out for me, because that would pretty much take me from really liking to loving it.