I've not read the whole thread, or report yet. However, there are many references here to lack of airspeed. Surely there was a ground speed readout. Thus there was not a total loss of speed indication. That info, coupled to basic power/attitude V/S could give some idea of what was going on. Easy to say from the arm chair, but I have tried it in the sim on TQ courses. OK, an approach is different to high level flying. Headwind/tail wind etc., but ground speed would change with attitude. Block the pitot tubes and fly an approach on groundspeed. It really emphasised that power/att V/S works. If they were confused by high nose no stall warning, low nose stall warning, then pause, consider and look for other clues. What does the ground speed do with change of attitude? That can at least confirm that the ASI is giving out B.S. At high level there is a lot of thinking time. Remember the BA 747 that had all 4 shutdown in volcanic ash over SE Asia. They had thinking time.
A scenario with loss of a primary parameter such as airspeed should be a recurrent training exercise. It has happened on enough occasions, resulting in a crash, to be included. In all cases the a/c was flying and controllable; either blocked pitot or staic vents. Sadly, many of the 3 year recuurency items are tick boxes. They are not related to real life incidents/accidents. If knowledge of these is not passed on and trained how will we learn and not prevent their re-occurence? After Hudson I know many airlines suddenly included loss of thrust and ditching. It was fun and ticked many boxes. The same after BA's B777 glider, but not Air Trans A330 glider. That would take too long in the sim. 30mins at least, but you would tick many boxes; flight controls, alt flap, alt gear, aircon & press, panic management, and it would be a great CRM exercise. Why was it not done before? Do we have to wait for another high profile crash to consider more meaningful recurrent training? With commercial pressure on crew resources training is diluted to minimums. The downward spiral is tightening.