OMG....I had misinterpreted this as I couldn't understand the guy's accent completely. Apparently what actually is happening in the video is that the female runner in green is THROWING the item to the older man who is following her (the one who falls) who CATCHES it. Then the guy in the blue jacket comes running up.

So it's NOT from the blast at the sideline, as I watched it carefully again this morning, it's FROM THE FEMALE RUNNER IN GREEN RIGHT IN FRONT OF HIM, THROWING IT BACK (whatever it is) TO THE OLDER MAN WHO THEN FALLS.

That is even MORE suspicious as one wonders...what the hell would you be throwing in the race? I might understand the old man reflexively catching something blasted in his direction, but this is a deliberate throw from the woman in green to him right behind her.

This is really bizarre. Fortunately more than one person on YT has this up.