The key point here is that they were not conducting a TEST of the system...they may have been misled by the incorrect depiction of the protection limits on the speed tape, but if they had considered a negative outcome to the 'test' they would have had ball park speeds noted- as soon as it became apparent that the FAC speeds were too low in comparison they would have had to resolve the ambiguity.
They were 'DEMOing' the kit and the kit failed - there was no plan B.
Ultimately human error again, unfortunately. Airline pilots, even TRI/TREs are not test pilots. I'm a TRE and I've spent this evening in the sim with two test pilots. Their training and their capacity to critically analyse a system is very different from mine.