Altitude - Distance
Isn't the point that whilst altitude is checked first, the distance has to be from the runway / threshold.
The intent is to achieve some independence from the FMS, ideally from DME, or if not, apply the small, simpler distance correction between the DH position and threshold.
Simple rules of thumb required - general awareness - I recall ‘never less than 150 ft RA until DH’.
EGPWS should have detected this event; T2CAS, not known, but very surprising if it isn't capable.