There were plenty of things wrong with Batman v Superman, just like there were plenty of things done right. One of the latter was the portrayal of Batman - and, of course, you'll agree if his murderous attitude didn’t bother you. And, concerning this character and his killing habits, one question arose: when did he start breaking his one single rule?
Most of us assume that it happened well before the events of Batman v Superman, and that it had something to do with a crucial event from his life. This event is just teased in Batman v Superman, when Robin's suit is showcased with Joker's writing on it. So, apparently, Batman decided to be unforgiving with the villains only after Robin's death.
However, CBM reports that it might not have been so. According to the Batman v Superman: Dawn of Justice Tech Manual, Robin's weapon of choice was nothing less than a halberd - as in, nobody would mess with someone with a halberd. So, apparently, if Robin used this weapon, a lot of maiming already happened to some baddies before his untimely death.
And if Robin did do that, who is to say that Batman didn't do it as well?
Obviously, the Batman v Superman Batmobile had some pretty neat (and deadly) machine guns attached to it. However, the Suicide Squad trailers show in the flashbacks that the Batmobile wasn't actually so menacing. Which one is true?
We are more inclined to believe that Robin went unchecked, rather than believing that Batman has always been, well, a Punisher. However, this doesn't explain how he didn't know that Robin was using such a deadly weapon.
And no - we don't believe that he'd frame the weapon that killed his sidekick.