It kept re-adding because the flap of the aoa sensor was stuck in the "aircraft is pitching up" position. Boeing management did not add a second sensor to some

It kept re-adding because the flap of the aoa sensor was stuck in the "aircraft is pitching up" position. Boeing management did not add a second sensor to some planes and also pilots were not aware of how to switch off mcas. If you worked in large scale project you would know that most devs are assigned components to work on and usually have no idea what other components are or how they will interact.