That deal with DC wasn't over Watchmen
. It was over V for Vendetta
, and it wasn't to do with the film rights (Moore had those and he sold them). That deal was to do with the V for Vendetta
publishing rights. Moore would have got ownership of the publishing rights if V for Vendetta
had gone out of print. But it never did because of its continuing popularity (something that Moore wouldn't have anticipated at the time the publishing deal was struck with DC because at that time a continuing backlist of graphic novels wasn't yet part of the industry). A lot of this stuff is in the thread I linked to above.