Just on this topic, may I pose another question.
You sign for an unaccompanied minor who clearly has a disability (travelling with brother and sister who are able but not old enough to care for him by definition), but not being an expert in this area, you give the benefit of the doubt and take them on board and commence your briefing to them, advising all the other crew of the situation.
The UM does not respond to your briefing, nor to your calm reassuring requests to fasten his belt, or pay attention to instructions relating what to do if the masks drop/where the exits are etc. You try your hardest to find a way to communicate, nothing works. Brother and sister dont want to be a part of it and pretend hes not even there.
You raise your concerns with crew and manager, and another crew member with a bit more experience with this particular disability takes over, and gets a better response from him.
Do you accept, with you name signed below his on the paperwork, or do you speak up and offload? (keeping in mind in an emergency, you may be his only chance of survival if other crew is incapacitated or unavailable).
I'm not going to say what happened, but would be keen to hear others 'professional opinions'.
(to add complication, your airline and other local airlines have been under fire recently due to poor handling of such situations by disability organisations and the media).