Software assumption
It appears sensor input failure was assumed as stall by the software. I wonder who designed that algorithm. I am sure pilots would disagree on such an algorithm. Interestingly aviation is not alone : Toyota brake failure, vw dsg failure, medicines sent out being recalled. Inadequately tested products, lax quality control, what if lives are lost the businessmen and organisations still not culpable or accountable! They offer free replacements of parts (for lives lost) and their lawyers cite disclaimers. When is this going to end? Only when the root person (in this case the software idiot) is singled out and publicly identified, their organisations named and shamed may be.