never be surprised by the conduct of one scouter to another. bsa really does tolerate some horrendous conduct directed from adults to adults and few who really have the power to at least attempt to right the wrongs are willing to put the effort in and make it work. even as we see on this board some of the conduct shown ....... well, at least the scouts themselves are never that bad. honestly that's the main thing that kept me on for years despite constant harassment by other adult leaders.
in situations such as these, i know its sad but it might be best to cut the losses and find another or form another troop. its impossible to continue without the support of the cor as others have also stated. i believe we got at least 1-2 families a year transferring troops because of bad situations, most of which weren't this bad.
as for the injury you received, im pretty sure that's more battery than assault and you can always try pursuing either criminal or civil charges. there are actual rules he did violate in the this act and they are listed in the code of ethics which considering fact this document also talks about things like membership fraud should give you the indication bsa buries these types of issues. i can guarantee if you pursue this route you might win the case but the council will truly hate you and you will never get their support for anything ever again.