 His absence from the regular armed forces was due to a corned beef allergy, although it was implied that Walker had probably found a way to play the system.Mainwaring often turned a blind eye to his profiteering as he could supply the platoon (and Mainwaring) with useful items.On more than one occasion, Walker's willingness to use underhand tactics allowed Mainwaring's platoon to triumph over rivals in the Home Guard, Army and ARP.