FCOM A320 - 1.27.30 Page 2
SmartCockpit - Airline training guides, Aviation, Operations, Safety
Please go to that page and take a look at the schematics. You'll find out the conditions for RECONFIGURATION CONTROL LAWS on A320. Maybe then, you may understand that,
despite of being highly improbable, one could fly in a situation where the aircraft doesn't downgrade to alternate law, trapping the pilot among protections "active" leading to lost control. If, by chance, for instance, you get wrong (yet within parameters) hight speed information
through all ADR's, the system will be
kept in Normal Law, and
High Speed Protection will keep active sending a nose up input and pilots will be unable to bring nose down. (That would be a case for a "Red Button" or a new logic to the instinctive disconnection push button, in order to bring the Law's to a degradation mode, where the pilot still have control of the aircraft).
Please tell me, if I'm wrong.

(I'd rather be wrong...)
P.S.- What is the probability of 4 engines failure? Yet it has happened ...