this part of the movie confused me... he threatens to kill grimlock if he doesn't help them and then once grimlock's his horsey he says that he's giving the dinobots their freedom?
This is a sign that Optimus finally lost his marbles after all he's been through all right. And I didn't get that scene either in the movie. I figured it was going to be Optimus earning Grimlock's respect and trust by trying to outmatch Grim in a fight that'll allow Grimlock to be impressed enough to help the Autobots which I would've prefered.