In Christopher Nolan's Dark Knight trilogy, Christian Bale's Bruce Wayne harped on his no-kill policy. It connected to Batman's modus operandi in so many comics, video games, cartoons, animated movies and even the live-action films prior. Over the years, however, viewers with critical eyes identified many sequences of Batman killing foes by accident when engaging in his acts of violence.
One recent example is Ben Affleck's brutal Batman beating down thugs mercilessly in Batman v Superman: Dawn of Justice's warehouse scene. Still, the Caped Crusader overall doesn't kill, which is what Bale's Batman kept trying to show the likes of Scarecrow, Joker, Bane and Talia al Ghul. However, one key incident in Batman Begins proved this stance was hypocritical and sadly, it brought a macabre element of karma over to Gotham.
Batman Begins' Bruce Killed Ra's al Ghul
The drama stems from Batman Begins' finale where Batman killed Ra's al Ghul. Bruce had Jim Gordon blow the tracks as the train careened towards Wayne Enterprises, knowing once the train veered off, it would stop vaporizing the city's water and spreading fear toxin. However, rather than rescue Ra's, he clamped him down to the train, saying he didn't have to kill the villain, but he didn't have to save him either.
The train crashed, killing Ra's in a nasty double standard. As awesome as Bale's Batman was, that's a cold-blooded kill. Whether it was direct or not, Bruce still played judge, jury and executioner. This is something other Batmen stay away from, even after villains like Joker killed or damaged members of Bruce's clan. Bruce should have arrested Ra's, put him on trial fairly and let the scales of justice sentence him to send a message to the world: Gotham is better than tyrants think, and won't sink to their depraved level.
Batman Begins Riled Up the League of Shadows
Bruce breaking his code is what riled up Talia al Ghul and Bane to hatch an elaborate scheme in The Dark Knight Rises, infiltrate Gotham, blow it up and make it a No Man's Land. While no one condones their attitude, this speaks to real-world issues where terrorist factions are emboldened when injustice is meted out to their tribes. These individuals become even more dedicated to the cause, thinking they're freedom fighters. In this case, Talia did see Bruce as a deceitful oppressor because he claimed to be a vigilante of honor, yet condemned Ra's who may have changed his mind after seeing Batman inspiring hope in Gotham.
This could have perpetuated a message to the League of Shadows that this city was worth saving without aggression. Instead, the League returned with lethal intent, taking Gotham hostage in the name of vengeance. Bruce clearly didn't believe in second chances, making the group more hateful. He showed them Ra's was right about Gotham being corrupt and filled with two-faced murderers. Ultimately, Bruce's decision cost a lot of lives and infrastructure. While he rescued Gotham with Catwoman's aid, he was responsible for the doom that came -- all due to a rash, emotional decision with his former mentor.