I think the guy first thumped and ran over got up again and ran after the elephant. It didn't stomp on him. Before being attacked he was right under its left tusk. Perhaps irritated it in some way?

Then it ran and attacked the other elephant.

Amazing how it goes from such a slow lumbering monstrosity into a fast able fleetfooted giant. A lesson to learn about them.

They are strong dangerous beasts, while domesticated, still have the physical power of a wild elephant.

Why wasn't they guy stepped on crushed? He got up and ran after the elephant trying to control it. Elephant in Africa when walking on sand only depress the sand a small amount. Wide flat soles space out the pressure and weight. The sand makes a quiet ssshhhhh sound as they depress it. In Kenya I've had more than one elephant walk past my head only feet away, less than six feet, while I was lying in a tent. What a sight looking up that would be with no tent in between!

I'm speculating the elephant stepping on the guy may have spread the weight? Unlike when an elephant stomps a person into mincemeat in an attack.