So you're telling me that he's on the far side of the truck, stretching his arms all the way across the back of the vehicle so that his right hand is that close to the near side of the truck? I don't believe it. It defies reason. I think Shades is right.
Further evidence that it's not true: There's another guy in the photo who is actually on the far side of the truck, pushing. He is, visually, just under the arms of the guy in the truck bed. His right hand is at the very edge of the far side of the vehicle. And he's not as high up as the guy in the truck bed, who would be standing just a couple feet behind him if he were not in the truck bed. And the far side of the truck bed occludes our view of his body, but not the legs of the guy who is in the truck bed.
All evidence in the photo affirms that one of the people attempted to push the vehicle is doing so from inside the truck bed.
But even if it is true that the guy who appears to be in the truck bed is actually on the far side of the truck, having to lean that far to the side would certainly remove virtually all of his leverage. So it just shows that no matter which is true about the position of his feet, he's not being very helpful in actually moving the vehicle.