I guess I can see the point this guy was trying to make, but first why did it have to be Batman who ended up making a mistake? Couldn't a cop or DA also make that same mistake? Furthermore, this is a hard sell when it comes to Batman, given his continuity as known by fans. We're talking about a man who saw his parents killed right in front of him as a boy; got hell from all his trainers as he prepared to become Batman; saw a close friend's double personality destroy him; after failing save a girl from drowning, got addicted to a steroid pill for which he had to lock himself in the cave for a month to recover from it(hence the unbelievability of the heroin addiction part); had his second Robin brutally murdered; had another sidekick (Barbara Gordon) paralyzed at the hands of the Joker; saw his other best friend, Gordon, stripped naked, tortured, and tormented with pictures of his daughter, also stripped, just after she had been shot and paralyzed; after going a week with less than a day's sleep rounding up all of Arkhum's inmates after they had escaped, got his back busted by steroid-laced madman; saw his beloved city have its own Black Death from the "Clench" virus, then further carnage when it got leveled by a 7 point earthquake.
With all that, why would Batman give in after finding out he unintentionally sent an innocent man to the slammer, then sent into a heroin trip, and raped? The man's been carrying guilt over his parents, Harvey Dent, Jason Todd, Barbara, Gordon, and recently his former mechanic Harold. What would be so special about this thief that he would take his own life, believing his crusade was in vain? If you want to do one better than Alan Moore (Watchmen) in debunking the whole concept of a hero, this ain't how you do it.