It is indeed a sobering thought, ..., that if the crew HAD tested the TOWS as per the apparent manufacturer's rec., before the return to stand, things could well have been different.
It's going to be interesting in the timing of this kind of test. Just how often and when?
Should it be in the takeoff checklist right before the crew call out green green for the flaps/slats. If not is there a chance that someday a crew does the check on taxi out then aborts the takeoff for any reason goes back to the stand and some maintainence function mistakenly disables the TOWS.
It's not easy to pick out the best solution without data and analysis of the Pro and Cons