Hi Max,
I've just read through this discussion and its an interesting read. You asked a good question, got good answers and a lot of opinions.
I think what zanthrus is saying is, "did you have enough information to satisfy yourself of your son's safety?" I think you didn't and therefore you made a logical and safe decision. Someone else in your position may have made more inquiries into what exactly was being organised and who would be flying the plane. Maybe, with more information, you might have made a different call. It doesn't matter, its not big a deal and maybe you will go on and organise a charter of your own with your son.
I'd suspect that even if you thought the operation was going to be a commercial charter you would still want know whose's the pilot and the organisation oversighting the whole thing.
Cheers Ted