Beside the medication, was he also getting the behavioral training that goes with autistic kids. Or was he just getting meds?
It is very difficult for me to believe or understand why anyone would diagnose a 2 year old with ODD and place him on psychotropic meds for years for this condition. Unfortunately, I think what you are currently seeing side effects, possibly permanent, to these strong medications. My only recommendation at this point would be to have him evaluated by perhaps another pediatrician to find out if the behaviors you are witnessing is a direct result of years of medication usage, if any of these behaviors are in fact permanent, and treatment alternatives.