The crux of the matter to me appears to be that the AoA failure, while certainly a "hole in the cheese", was secondary to a failure on the part of the humans involved - from the hapless ground staff who used incorrect procedures to rinse the aircraft, to the crew who failed to plan their test cycles correctly and then carried them out in a haphazard manner.
Sensor failure is something that can trip a crew working to IFR up no matter what they are flying. I'm reminded of the BirgenAir accident where the cause of the crew's disorientation was undoubtedly a blocked pitot probe feeding the Captain's panel, but the fact remained that the crew should have aborted the flight and returned to land the second they saw a discrepancy in airspeed indication (which, as I recall, first manifested on the runway).