Actually, that's not what he's saying. It wasn't Two-Face, but an original character that Engleheart created. He was a goody two shoes politician with blond hair who stole Batman's former girlfriend. And then he got attacked and basically turned into the same thing Two-Face is. So the amusing thing is, Engleheart created a Two-Face clone, and then went on to claim that his clone is being plagiarized in the depiction of the real deal.

Gotta love it when someone comes on and decides to take up the thankless task of "enlightening" the ignorant masses.

Your first mistake was to assume that everyone here thinks TDK is the be all end all of all things Batman. Just by looking at some of the names in this topic, I can tell you that you're throwing the "worshiping" accusation at the wrong crowd entirely.
It's not unusual for a character to have their hair color or even
race changed in a movie adaptation (i.e. Harvey Dent in Batman 89, Kingpin in Daredevil, Ra's al Ghul in Batman Begins), so I can't even believe that he's using that argument. And like I pointed out earlier with the Spider-Man 3 example, it's not unusual for a hero to have his love interest stolen away from him, either.
What he says is plagiarism, I say is coincidence at best, and that will continue to be my position until Goyer or one of the Nolans cites this comic as an influence. They'd have no reason not to, since they're pretty straightforward with what comics influence these films. I'm not saying that because I "worship" the film. It's my favorite of the live action films, but I find Mask of the Phantasm to be just as good if not better. I simply don't find Engleheart's argument to be a very convincing one, and that's that.
And while I admit that the character Engleheart created does bear a strong resemblance to Aaron Eckhart, I found this statement to be amusing.I'm... pretty sure that Eckhart was born long before his Dark Detective comic was published.

And he even tries to claim that the movie's title was stolen! Come on now. Batman's been called "The Dark Knight" almost since his creation. Saying that the movie was called that to make it similar to the title "Dark Detective" is really stretching things.