This question was prompted by discussion here.
In Supergirl S05E09, the first episode of the Crisis on Infinite Earths crossover, there is a brief scene set in the universe of the Tim Burton Batman films, featuring the character of Alexander Knox:
The headline of the newspaper Knox is reading proclaims: "Batman Captures Joker". But I don't see how that's possible, because this universe's Joker fell to his death at the end of Batman (1989).
How can this headline be correct? Is it a retcon? A different Joker than Jack Napier? Or just a simple production error?