IRA’s contempt for McConville and family

Surely Mr Adams would know, or at least want to know — if not demand to know — who the sociopath in the ranks of the IRA was. Were there no questions asked? Was anyone held to account for what really was a “war crime”, as Jean’s son Michael has said?
Or was he rewarded, promoted, decorated, or given a political career as Sinn Féin tend to complain about in relation to the British army?