after olympic tornado sailors and 49er sailor drowned by beeing caught, it really seems to be a topic to consider.

i have capsized many many times and surely also my trapeze hook got caught somewhere else. what always helped me is to keep calm in your mind. if you don't panic, you can analyze where you got stucked and in which direction you have to push or pull to free yourself. basically I believe I will always be able to free myself easily. but the tornado and 49er sailors might have thought the same. so basically it is good that those harnesses are reconsidered, although I believe the danger comes more from flying agains a daggerboard, hit the rigging etc...

but again, this is seldom and still a lot of people die just by crossing the street which might still be more dangerous than capsizing with a catamaran...

for your son, I would invest into the new magic marine trapeze harnesses (although it is very difficult to reattach it and children have the tendency to play with things parents say 'no'...)

secondly i would advise you to buy him a small emergency signal he can shoot easily in the air. 'nico' offers a four-shoot device which could also be handled by a responsible youngster. you should have one as well.

third advice regards only yourself:
beeing a singlehanded sailor since several years and once lost contact to my boat on the eastsea swimming for half an hour before someone picked me up, the easiest solution is that you get one of those shackles winddragonflyer are using. such a shackle you attach to your trapeze trouwser and than you put your mainsheet which is connected to the travellersheet through it. you can also use a normal swiftshackle but the advantage of the one I mentioned is you can open it under load! beeing attached to the mainsheet will make it nearly impossible to loose contact to the boat!

and than don't worry to much! fear is always the best route to end up in trouble...