Having been in a similar situation (being the injured party), the system of Values and Standards including AGAI allways comes down to the service question before any form of punishment or retribution can be brought forward. This can take an age to be processed. If the service question has been failed then the Officer in question should be brought before the bench and the appropriate action taken. However in a TA unit it would be difficult to put the service question into it's correct perspective.
What would I do? Go to an officer I know and trust to do the right thing (could be the CO, 2IC or TM or the OC) and make my complaint formally. Either way, its doing right by the injured party and ensuring this to$$er is no longer commanding soldiers.