Very true.
When sensors go rogue and the system cannot reject them and the wrong information is used by the system, danger is extremely high.
When that happens it is better to revert to alternate law, by getting rid of the rogue sensors. No need for Direct law. But if it takes to go direct for whatever reason, then don't hesitate, of course...
in mechanical law, I would feel OK if I expect to recover something and go into direct or alternate. But If that is not possible, I will not feel OK anymore, for most likely I am going to die.