So what’s the point of fretting about authorship? (Can’t we all just, you know, get along?) There are sequences in “Babel” where you can sense the tenuous symbiosis of writer and director starting to fall apart – when Mr. González Iñárritu overextends scenes for, apparently, no sounder reason than to demonstrate his virtuosity, prove he’s in charge. It’s as if these two extremely talented men had not understood their own movies, which are bracingly (and movingly) skeptical that an individual can ever be fully in charge of anything. The action is always set in motion by an awful, senseless, out-of-the-blue accident, and that’s a slap in the face to the whole idea of authorship: you can’t even count on being the author of your own fate.