People like just jude love a rant even when they don't know all the facts.
My son used to be in the scouts, and one of the children in his group would have died if they came in contact with peanut oil. Even if it was only on someones finger tips.
Most chocolate bars are made in an environment were peanuts and other nuts are used, so having ANY chocolate bar could be fatal to another child with nut allergy.
So for that reason chocolate bars are banned, and the mother probably signed a letter to say she accepted that, but then probably forgot.
But if a child with nut allergy had died on the school trip you would have probably moaned that the children's bags were not searched to find any chocolate bars.
But never mind Just Jude you have a rant a the "stupid" teachers as you seem to know everything.