I am not sure I understand what the mechanics are being currently subjected to :
First : Are they just "imputaded " to be heard by the judges to find out what they actually did to the aircraft prior the accident ( I could go along with that ) or is there an attempt to use them as (low rank) scapegoats for that accident ?
Secondly , in the SOPs, is the TOWS a safety net , or a tool ?
In my area of work , the failure of a safety net warning system in our (ATC) systems cannot be used to justify an incident/accident. It may contribute to it, but cannot be the cause.
The same in real life I would say : the failure ( or non-vailibility ) of the ABS on your car will not be the cause of the accident you may have .