Verify results : The reason to possibilities bring toward on the root cause. that so after pass is removed solder mask malformation looks like is open scratch handling or mistake verify cut short on the circuit line. another side defect it, that 's resemble affect was pass high voltage (blow up) step verify detect where short defect area it. indeed concluded so it mean to sharp thing interruption to affected the functional.
Aspect assumption to bring about was caused, the concerning operator was poor training and don' t know about the defect in working time. that truly will must to scrap or accept it. which this issued, it must separate scrap only. but operator was doing solder mask touch up it. the conclusion occurrence the trace damaged was happened from board finally, the operator was over look on the defect board during did 100 % inspection before & after finished surface to cause open circuit flow out to customer. please consider and decide the indication for depletion as a possible the root cause or not. refer to the details in the image above.