The Disposal and Liquidation Commission was not a military body. It was a Treasury body, set up when the Ministry of Munitions was abolished "to exercise such of the powers and duties transferred to the Treasury.... as related to the disposal of surplus Government property , the completion and liquidation of contracts and other liabilities of the Ministry."
As such it would not have access to army service records. No doubt references would have been sought, and we might surmise that HWP would have nominated a friendly former officer or two as referees.
I wonder if his guilty plea in 1917 had saved his CO from investigation.