In answer to the comment, "The one thing that I don't understand is why no-one went to get the parents of the children who were dumped and misbehaving."

Who knows which adults and which children in a large group of strangers go together? It took a while for us to figure out that no one in the room was responsible for the children.

The insight I am trying to share with people is that when children are tired, they tend to get wilder and wilder, whereas adults get quieter and quieter. This is something to be aware of, whether they are your own children or someone else's.