Here's a clip from 'Eagle Eye' that shows (part of) what I assume is Billy Bob Thornton's metamorphosis from antagonist to protagonist. Thornton plays an investigator who, initially at least, assumes Shia LeBeouf is lying when he claims he was framed by some mysterious group that planted weapons and money in his apartment to make it look like he is a terrorist. (I really hate when that happens).
Problem is, now this is all speculation (I would never spill the beans if I knew I was right), Thornton's character would be too much of a one note kind of guy if he never figured out poor Shia was telling the truth and helped the kid out. Sort of like Tommy Lee Jones' character in 'The Fugutive', except, logistically, Thornton's character has to catch on sometime in Act II in order to be effective.
The scene, if I'm right, would be one of the early turning points. By this time Thornton would have at least voiced the opinion that something about Shia being a terrorist just doesn't add up. Scene would serve to get the audience's support for Thornton, setting him up to discover the truth later and going after Shia, not to apprehend him, but to save him and help stop the bad guys. This turn around should help prevent an Act II sag and drive the action into Act III with some snap.
Of course, we've seen it all before, but the energy and rhythm are just so and I think audiences will respond. So far, everything I've seen from 'Eagle Eye' has it shaping up to succeed at the box office. All they need is a good ending people will talk about.
Here's another clip. This one is pretty generic. I don't suppose there is much analysis possible. This is a chase scene involving a way too advanced drone plane, a car, and a tunnel. Some fancy driving, and an explosion or two -- pretty standard stuff -- but, again, the rhythm is spot on. What's new has just the right energy and what we've seen before is tight. No loose ends here.