I hadn't thought of the system crashes. I believe the way the system works is the ump wears an earpiece and either hears "Strike" or nothing at all for each pitch. If the system malfunctions, he would hear nothing even if it's clearly a strike. I also worry about umps trying to play the hero and ignoring what the earpiece tells them.
I appreciate you laying out your thoughts, CHL. I understand what you're saying about the limitations of the system, but moving to a challenge system is already submitting to its use as the "authority". And once we get to that point, why not make every call correctly and instantly according to that system? Issues like pitches being too low where they shouldn't be considered a strike can be addressed by modifying the strike zone box. They are already taking into account each player's height, so that type of modification, if needed, would be trivial.
I keep going back to this: in five years, when the fully automated system is in place, will there be any baseball fans anywhere who reminisce about the "good ole days" when a horrible pitch call could swing an entire game? When some balls were strikes and some strikes were balls? I can't imagine that will be the case.