Originally Posted by theMan-Bat
It proves that he didn't copy any ideas from the cartoon, since the cartoon hadn't even aired yet.
The episode didn't air yet, but was in production way before that and you know, Warner Bros. owns DC and Brennert and Miller might know each other. You cannot rule this out.
Mr Man-Bat, you'd be a lousy detective.
Frank Miller was aware that he was making changes to Batman's history. But as Miller stated in Amazing Heroes #102 (1986), "I'm doing nothing that violates major aspects of continuity. I'm embellishing his beginning. You might say that the first issue of Batman: Year One takes place between panels of the old 'Batman: Who He Is And How He Came To Be' (in Detective Comics #33) and the rest of Batman: Year One takes place between that the first story (in Detective Comics #27). I like not betraying the original material because I think it's to good to betray." Frank Miller explained, "Denny O'Neil and I agreed that it wasn't necessary to start Batman over, to scrap continuity, because the character didn't seem to need it." Year One explicitly contradicts only a few Batman tales before 1986. Which means that most of them were left still intact. Frank Miller definitely had knowledge of Batman history as he brought Batman closer to his Golden Age roots. First is the use of the bat emblem on his chest without the yellow moon in Batman The Dark Knight Returns. In the Golden Age this was the standard. Batman carrying and using guns, which hadn't been seen since 1940. Frank Miller brought back Robin's sling shot which had not been seen since 1940. The gadgets and bat vehicles which had been toned way down in the '70s. Batman originally was a terror striking creature of the night wanted by the police. Batman: The Dark Knight Returns and Batman: Year One returned to that concept.
Miller made Gordon much younger.
Gordon is not from Gotham City.
Miller didn't feature a friendship between Bruce Wayne and Gordon.
He originally wanted to make the child of Gordon a girl (Barbara Gordon, batgirl), but then someone pointed out that she would be way too young.
He made Alfred the old family retainer.
Batman did face the Joker for the first time with Robin, not alone.
Gordon was not an adulterer.
Catwoman was not a dominatrix and was called "The Cat".
And so on. Like he did with "The Spirit" he just didn't even bother.
Of course, Denny O'Neil didn't even bother to stop him ("best Batman editor ever", LOL) - a little bit of tweaking would have kept the old stuff truly in canon. (I guess, Mr ManBat, that would have been "censorship" according to you)