I already answered the first question. If you above all the surfers, you can't hit them, because the ocean is at the same altitude everywhere in the world. He had to be flying backward, to get the fronts of the surfers.
As far as the done rules, if you obeyed all the drone rules, it wouldn't be worth having a drone. You just have to use your common sense, until they make the rules more intelligent. I think most drone pilots agree, that some rules don't make sense.
He might not reply to you, because you pissed him off.
So in Australia this is the rule: "You must keep your drone at least 30 metres away from other people." But what do they mean by "other people". If you know them are they other people?