I’m pretty sure that it was before 2007 that the Boy Scouts instituted a policy that no adult leader could be alone with a scout. They all had to go through training and there had to always be at least two leaders. Four of my nephews are Eagle Scouts and at least two of them and my brother have all served as leaders so I’m pretty sure of that policy. If there was a scout sponsored event and the policy was not followed, then the scouts get sued. Organizations like the scouts, sports, churches have always drawn pedophiles and kids have been molested. Its only been in the past few years that there have been screenings, training, and policies. When my son was doing community theater at the age of 12, small for his age, blond, very cute, I went to all the rehearsals and shows and if I could get away with it, lurked back stage. Same with wrestling. This was 15 years ago.
The requirement of two-deep leadership was a part of Youth Protection guidelines long before 2007.
However, a Scout Leader who wants to molest a boy is going to ignore that rule. The two-deep leadership rule only works if the other adult leaders are alert to what is going on and don't let any leader have one-on-one contact with a Scout.