Earlier quoted context omitted.
How can Google be sure? They can't, so they can't do it
Sure they could. Copyright owners could list the content they own in some centralized system, and provide canonical URLs or domains for accessing that content. Google could then show that a particular search result is the canonical page for a given movie, without having to try to guess whether some other page has an illegal copy.
Basically, you're wishing away a number of huge problems, including (1.) that copyright attaches at the time of creation, while the owner of that copyright is often multiple steps removed from the act of creation and determined by complex legal arrangements; (2.) copyright ownership for a particular work may differ depending on political jurisdiction; (3.) copyright ownership is not the same as distribution rights, which also may vary based on political jurisdiction; (4.) it's not clear how fair use could be accommodated in such a system. It would also have the effect of favoring larger entities with more copyrighted works; i.e. Disney would have a better chance of navigating this system than an independent creator would.