You have to listen to what Arthur says in his apology I think. He clearly says he was young and it was his first mission. He wanted to impress his father, but had no control over his men or himself. He froze instead of leading. All this implies that this was indeed pre Merlin, probably a teenage Arthur just knighted by his father and sent out on a mission. By the time A Nightmare Begins we have seen Arthur lead the knights and going on patrols and doing Uther's bidding with apparent ease. We know he is the leader of the knights thanks to the whole Lancelot ep and the numerous training scenes with Merlin. And he's at least 21 by that time, not the insecure teenager, but a arrogant young man, confident he's the best solider in Camelot as was implied the first two seasons. Not only that but he certainly did not freeze up when attacking the Druid camp holding Morgana. That was a confidant solider leading his men, giving orders etc.
Not only that but in Nightmare he had a justified reason for going after the Druids. To his mind Morgana had been kidnapped by them, therefore there was noting to apologize for, he was doing his duty and rescuing the Kings Ward.I don't see him apologetic over that incident.
Edited by rtms, Dec 4, 2011 @ 11:18 AM.