Hi,
Since PF & PNF had apparently not had a chance to demonstrate flight in cruise in ALT2 law under UAS conditions, they were open to uncorrected misunderstandings.
Open to everything specially in EXTREME conditions.
but if the airplane "knows" it's in UAS, there's no excuse for it not to use every means to notify the pilots.
The information (Pitot's "garbage out") is available. The System (a subsystem) could easily process and present the results. How? This must be studied. The interface must be always kept simple. K.I.S.S. principle is mandatory to the interface characteristics.
PS
HF study could be extended to upper management, bean counter's and System designers. 
.
In order to understand why they fail. 
And to improve man machine interface.