It seems to me, most of this is covered under YP guidelines.
In the GTSS (orange cover, pg. 6, in bold it says "All members of the Boy Scouts of America are expected to conduct themselves in accordance with the principles set forth in the Scout Oath and Law. Physical violence, hazing, bullying, theft, verbal insults, and drugs and alcohol have no place in the Scouting program and may result in the revocation of a Scout's membership in the unit."
The Troop Committee Guidebook, 2004 publication date, does address physical abuse on pg. 40 in reference to YP and further states, "If at any time you suspect an instance of child abuse within the Scouting movement, you must contact your local council Scouting Executive immediately."
I'm amazed that it appears yor Troop Committee has not acted on this. It's one thing for a couple of boys to be fooling around but for an adult to get involved like that, yikes! my skin is crawling! This certainly wouldn't excuse it but had he also been drinking? That would be yet another issue.