Certainly, if all landing gears were found in the down and locked position, and the gear handle also down, it would add credence to the theory that the gear was deliberately selected down!
Dont discount the fact that the 'freefall' mechanism for emergency gear lowering in the metros is cable operated to the mains and nose. It unlocks the uplocks. These cables would most likely have been pulled taut as the airframe broke up, releasing the uplocks.