There are a lot of very real conspiracies in this world. Many famous conspiracy theories do appear to be true.
But this one is just a bunch of bullshit. We all saw the bomb go off, people got blasted. I don't see why they would fake this guy's injuries.
But hey, who knows.... there's really no limits to what the cia will do. Maybe this guy is a cia asset planted on the scene for some reason? To create a spectacle for the cameras, and with fake injuries he'll be sure to survive and work his spin.
Anything is possible. But this conspiracy doesn't have me convinced.