sorry for injecting this, I'm usually wiser than to sepak up around you guys, but:
afair, the Birgenair 757 that crashed in the Dominican Republic in 1996 did so because of a clogged LHS pitot.
The A/P took it's speed reading from there and, as the static pressure decreased faster than the residual pressure inside the pitot, the indicated speed increased, causing the A/P to throttle back and pitch up to bleed off speed.
That's 13 years ago, and today we're seeing another accident, where the malfunction of one instance of a redundant instrument causes the A/T & A/P to fly the aircraft into a stall?
Should the systems not honor the redundancy and use the alternate system if one them signals a malfunction or at least the readings are wildly inconsistent?
There are probably more factors to consider than what I know, though.
Shortly after the Birgenair event, I got a chance to ride a 757 sim and the guys took me through the accident. There were multiple opportunities to save the day for the crew, had they interpreted the situation correctly and acted accordingly. I wonder if that wasn't true for this accident here.
But still: it seems that the system in both cases has failed and in doing so has not failed to safety.
and with that thought, I'll retract to silence again, leaving the discussion to those who know more than I.