Perhaps as you say with hindsight (which is as always is a wonderful thing) this was a foolish, stupid and irresponsible thing to do.
However making an apology (It takes a bigger person to say sorry than one who chooses to ignore or refute) via as many social media points as you use is a start. However as many point out it just re-ignited the whole unsavoury motorhome issue up there. Perhaps a letter to the media (local or national papers) would also have seen this 'prank' having been highlighted and the accompanying letter of apology, donation etc all covered giving the true account and result instead of allowing the scab to regrow over old wounds.
Unfortunately far too many who travel up there (and other places too it's not just an NC500 issue) do so as non regular motor-homers and treat the countryside as their personal rubbish tip. Enjoying their own views but having no concern or thought for others as they do so. An irresponsible Motor-homer/Driver/visitor will have 100 complainers spreading the negative word, whereas a responsible one will see perhaps 10 spread that positive word.
A lesson learned I hope.