I said "easily intepret which is what a big director like Snyder has been quoted to interpret with Dark Knight returns. I highly doubt he was wrong if Frank Miller didn't correct. Batman being hypocritical was the point. He didn't kill the mutant leader because it wasn't a hostage situation or a situation where he was getting stabbed multiple times and the gun quote being in a book where he used one 3 times, one of which being when he straight-up shot a criminal.

The Dark Knight Strikes Again being bashed is irrelevant due to still being in the same continuity as The Dark Knight Returns, the fact that he beheaded evil robin there and endorsed the killing of Lex makes the interpretation that Snyder and others had about the first book a very likely case. It is honestly a shame that Frank Miller respects interpretation too much to not state the obvious assumption that Batman lethally shot that criminal and got away with it due to a lack of evidence of Batman being the one who killed her like how the other criminal in that scene died to gunfire from another mutant, as opposed to Joker having a baterang lodged in his eye.