I'd say Keaton is pretty vicious about it.
Smiling sadistically as he sends a strongman tumbling into a ditch and with a bomb strapped around his waist is pretty vicious. Likewise, turning his Batmobile around so that he could incinerate someone is maybe the most brutal kill in any Batman movie.
And Bale basically looks a man dead in the eye and says 'I am going to let you die in this monorail accident that I planned and orchestrated with Jim Gordon'.
Anyways I'm not disputing your overall point, obviously, I just thought that singular point was arguable at the very least.