Difficult to be sure, although there's software available that will analyse an image and look for signs of alterations, but if I was forced to choose I'd say it looked Photoshopped. It's been quite well done if it has, but there's something about the brightness and contrast of his image vs that of the background that could be suspect. There's too much well lit detail on his 'shadow side', as though the sun was coming from behind him in the original shot and a new one has been added to his right.
Of course I'm only a half decent camera nerd. You need to ferret out the definitive truth elsewhere
And I'm no biker but I'd have thought he'd be looking the other way too.
Whilst praying......
Edit: I'm looking at it on a much better monitor at home now and have even less doubt - I'm sure it's been chopped and 'shopped
