The "AOA DISAGREE" indication is at the bottom of the screen, in minuscule amber letters on a brown background. It is barely legible in the photo and certainly not likely to attract much attention, particularly if the aircraft is behaving in other distracting ways. Indeed, not only were the crew poorly-informed about MCAS, they certainly would be unlikely to link this to a miniature "AOA disagree" sign. Even if it flashes (does it?); to say proudly that "WE have an "AOA disagree!" warning light", is one of the most pathetic excuses that I have ever heard (and believe me, I've heard a lot).
I too, have an interest in safety, although of a rather different kind.
Mac