Kickoff play

[PSU213]

I agree with everything said so far. Its not a matter of force at all. There is really only 2 rules in play. One is the definition of a kick, specifically that a kick doesn't end until someone possesses the ball, and second, that any kick into R's EZ is always a TB the moment it crosses the plane of the GL. The fact that anyone has provided a new force to the grounded kick has zero bearing.

As for the coach, give him a quick explanation, but don't hold the game up. The rules handle this situation so clearly that there should really be no discussion other than to inform the coach of the rule.