I think it comes down to the actions.

By the time Khan heard him curse, LeeRoy was well on his way to the ground, then he saw the thing and knew what it was and took off. And managed to avoid any extra damage due to a random wall coming into play.

Which means, Khan is incredibly fast(and honestly, I'm having trouble seeing him as intermediate), or LeeRoy's big ass falls slower than they fall in slow motion movies. 

Not to take into consideration, which side Khan was on - but I'm fine with assuming he was on the favorable side.