A short interjection into the 4 seat trial debate. I do them, they account for approximately 10-15 percent of my instructional hours and I should add that as a school we are at pains to point out that they are Lessons not jolly joy rides, despite having a pax (usually the purchaser)sat in the back.
I have always understood any trial lesson to be Excercise 3- Air Experience and this is how my students log it. It is fair to say that it is used as come-on for a full course of lessons and as such the name of the game is to enjoy the experience giving as much time as possible at the controls in order to show them that flying is not beyond anyone of average co-ordination and intelligence.
Anyway i'm rambling now but what I wanted to say is that the fact that this unfortunate flight had extra people on board probably had nothing whatsoever to do with the accident, and those who imply that it did are guilty of the usual crime of second guessing a pilot who cant answer back.