To me it comes off as an ‘I don’t know the difference between Boy Scouts and Cub Scouts and don’t care to’ attitude. That the guy doesn’t know the difference just reinforces the stereotype that he is a goon who wasn’t brought up with wholesome values or in the type of home where he would have found out about Scouting. The jerk probably doesn’t realize that he basically said was that it made no difference to him if the boy was in High School or still young enough to be in Elementary school, he would still try to intimidate him. What a jackass.
That is precisely how it came across to me as well, snide, insulting tone, even if I didn't hear it said directly.
I agree with the rest of your post as well, bad enough he thinks to hassle or intimidate a young man, but for heaven's sake, a child, elementary school Cubbie??
More and more, union = goon