I don't think they will change things to stop people pulling the boss while the cutscene is active unfortunately as I suspect it might not be very simple to implement and would be very unpopular among a lot of players sadly. As for the player, reporting was the right thing to do. Regardless of the reason there is no justification for not being civil to other players, particularly new players and particularly when veterans get the bonus.

Sadly these types will inevitably pop up in any community and an online one is no different. The best solution is to report so the rules can be enforced and so the threat of repercussions can either keep people from acting that way or make them move on. Nothing slows down progression on a character like a 3 day ban.