I just read the BSA rules on the net. I was a Life Scout. There were plenty of times a Scout would stay behind with an adult, and no one would even dream that any of the adults were child molesters. The suggestion would generate at least a broken nose, and most likely be worse. I'll never understand, or condone this suspicion, or overkill that every adult is a closet child molester. All those times I sat in discussion and conference with some adult connected with scouting would be banned today, and the adult would be considered more, or less a criminal with ulterior motives.
The BSA rules you read on the net are the tip of the iceburg -- there's an entire Guide to Safe Scouting that's updated regularly, together with a dual video component.
The world is not the same as it used to be. Our son ten and is in Scouts. And the leaders are nice enough people, they seem responsible. But, I ask myself, do I really KNOW Mr. Smith? We go camping with him and his son, but I don't know him. I would much rather have my son camping with Mr. Smith, and my son's Daddy. Having a parent there is much safer.