Getting home early is not an emergency, I agree - but surely it would have been better for 18 soaked Brownies to have been picked up as soon as possible, so that their equally soaked - and tired - Leaders could have gone home for a hot shower and a rest, SeptemberBabies?
Might it not have been better for one of the Leaders to ring the home contact and ask them to ring round the parents to say they'd be home early? They could have done this from the coach, and all the parents could have picked their Brownies up when they got back - instead of which they all had to stand around, wet and cold. I don't think the OP is wrong to think this is not the best way things could have been done.
And I think you have missed the part where the OP was about take her child away without any of the Leaders checking her off their list, or noticing that she had gone? If she hadn't realised that no-one had noticed her collecting her child, how would the Leaders have known, for sure, that the child had been collected by her parent, and hadn't just wandered off?
Yes, these young women are volunteers, doing an amazing thing - but surely, if there are lapses in procedure, you, as a District Commissioner, would want those addressed in some way - politely, reasonably and fairly, of course. Everyone is human, we all know this - but if a lapse happens, that could potentially have led to a serious incident, isn't it better that this is flagged up so it can be dealt with correctly, and doesn't happen again - with serious consequences, this time?
Which is worse - a set of young Leaders is reminded that they need to hand over each Brownie at the end of a trip, and check them off on their list, or that they aren't reminded about this, and the next time a Brownie wanders off and something bad happens - they get lost/distressed/hurt?
And would it be so bad if they were reminded to ring the home contact if the trip is getting back early - so that the Brownies are picked up promptly and they get to go home sooner?