This washer filled on its own and the door locked

This washer filled on its own and the door locked. I ordered a new valve, as this water valve has been on back order for quite a while. Is their a safety mechanism for the washer door to lock on its own if the valve fails? Do I need to be looking at a failure in the pressure switch or control as well. I shut off the water supply at the wall and then after I left the customer turned them back on and tried to wash a load of clothes and flooded the laundry room. Thank you in advance for your ideas.