I'm a white haired kitesurfer, I might not be an extreme kiter but I am on the water cruising and jumping for the day, not just an hour or two. If you really want to get in on current kite teaching action you better start considering it a family sport. Last August I stopped in Hood River Oregon and found I was one of many "old guys" (and gals) on the water. Wake up and smell the money!
Regarding the accident? I would recommend no more than 2 in a class. Though I know there are places with as many as 8:1 student teacher ratio, there is no way an instructor can effectively and safely handle 4 or more students.

Yes I feel we all thought KNIFE at the same point in the story. But there wasn't and someone has paid the ultimate price.

I can only imagine how this instructor is feeling and trying to cope with this tragedy not to mention the deceased family.

Brave chap letting us all know the exact details and yes it was a chilling story, even more so that is was true.

Rest in peace.