Can any of us - let alone another player - ever be "reasonably certain" of anything these kids are going to do? Was it reasonably certain the defender actually trying to block the kick or tackle the runner? In this scenario, if I had to make a call, it would depend on if the contact were "bang-bang" (for want of a better expression) or a count delayed. The former gets a "pass" and the latter .
Let's ban Rugby-style kicks
Forgive me, but
YOU CAN MAKE THE CALL when you're wearing the White Hat. That's not intended as an argument or a challenge to your judgment, as much as this is simply the Referee's call. The rules makers (and common sense) have never been in favor of judgment calls being decided by majority rule. That is a slippery slope that will produce ONLY disaster.
In this case it's the EXCLUSIVE judgment of the Referee (hopefully supported by experience, rules knowledge, proper positioning and common sense) to determine what HE observes as violating the appropriate rule. As suggested, there have never been, nor will there ever be, two football plays EXACTLY alike, so the next rugby kick, roughing situation will be ENTIRELY NEW and subject to the judgment of THAT Referee.
God willing, it will be the correct call, but either way, it will be what it will be, and hopefully the entire crew will support their Referee's judgment and decision despite external criticism or question.