I think it's real but it's essentially an optical illusion. It's not a couple of inches off his head at all, it just appears that way because of the perspective.
I imagine the actual distance was 5 metres or so.
If it had been within inches, I don't think it would have injured him or blown his eardrums (especially since he's wearing ear defenders) but it certainly would have made him stumble a little.
Edit: In fact I've had a look through the video and the jet is at least 5-6 feet above his head. If you look at the shadow of the man it is directly to his right (sun directly to his left). If you manage to pause the film when the jet's shadow is incidental then it's not even in frame;
Note that the bit of the aircraft you can see in the frame is ghosting (a residual image). This is obviously the case if you watch the video and stop it intermittently. The ghosting is obvious. If you don't believe me/can't see it on the video, then think about the size of that man and the size of the wing in comparison lol. It is not the plane, it is where the plane was some distance away.
The shadows are perfectly aligned, and because they lie at a cardinal angle you do not have to account for perspective. As you can see the jet is not in frame.