It is hard to tell exactly what this guy was doing.
The explosion was on his upper thigh and his hand was down but it could not have been very big.
The lack of heavy bleeding is the arteries pulling back in the body.
The trouble with any form of explosion is that the human body and explosions are NOT predictable.
I have seen a human close to a bomb being blown some distance away and other than concussion, blown eardrums and bruising she was ok.
Some one standing futher away had limbs ripped off, go figure I can never figure out why.