in fairness, that switchgear which had the relay in question does below to the superdome, not Entergy.
Does it? There may be a question of operation though. Whoever programmed the relay should take responsibility of the equipment it controls. Now there may be a lack of communication between the dome and Entergy regarding the profile of the load and all its characteristics. But the relay engineer is on the hook for this one.
A faulty piece of equipment, if it's a manufacturing defect, would be caught well before putting it in service. If the damage happened after installation and commissioning, it would be very easy to determine.