Yezzir. Paid a dude last night for that.
Hope you downloaded it, Microsoft's waging war on every Halo 4 video currently out there. It's gone now.
Halo 4's campaign is so public, I'm not sure why you paid for it?
And halo 4 is currently unreleased. It releases in November. He probably doesn't want to pirate it just to play the campaign early.