MRT recent train disruptions due to faulty cables - who is to bear the loss

About 6 months ago, I posted on my facebook wall that the root cause of the recent spates of MRT trains breakdowns was electrical and I wondered why the judge and prosecutor has not raised this issue in the inquiry into the matter and why the department concerned has failed to check the factory mill certificate on the cable specifications. True to this prediction, now Minister Lui Tuck Yew has had to admit that the cables were at fault and they have to be replaced at a total cost of some S$13-14 millions. One wonders why this matter was not properly investigated in the inquiry and it is only after the inquiry that the public has had to face a collosal bill of S$14 mil. Who is to bear this loss?