Ha! They used the ending from an earlier draft, where Dan and Adrian had an EPIC MORTAL KOMBAT FIGHT SCENE at the end, and Adrian was killed by having the Owlship crush him. I was so glad they cut that shit out of the film, good lord. Apparently that was one of the many things Snyder had to convince the studio to not do, and thank god he did.
However you felt about WATCHMEN, know that it could *easily* have been much worse.