I've been thinking about solutions as well; I've just been watching a mate at a Motorkhana today, where there are all manner of vehicles in various stages of fast road/rally prep.
Couple of cars were running bonnet pins, some had a wire external release... but I was thinking about the fire side and thought of the cat's arsehole solution (add in I've just come back from a friends place where the cats were walking around with their tails up...as they do...)
A couple of holes in the bonnet sealed with a rubber flap that is split into pizza slices (as such) that allows a fire extinguisher end to be shoved in and flood the engine bay without having to open the bonnet up.
Not 100% sure that it would work, but more food for thought...
Glad to hear that everyone is OK, and I'm a big believer in these reflective periods to not be a witch hunt, but instead a period to share ideas and learn things. We went to a lessons learnt approach rather than a incident report when I worked in outdoor education.