Auditing government transactions

In the spate of controversies regarding government transactions, taxpayers are always in a quandary where have those millions and billions of pesos are being spent. COA, the government's auditing arm considered to be as the last bastion for good governance, is now being painted as a graft-ridden agency. Knowing that their responsibility is to check irregularities in all government transactions, their findings are critical in restoring the faith in government service. As we all know, "public service is a public trust". In the case of Ms. Heidi Mendoza a former auditor, her explosive expose' has started the ball rolling on the plunder case filed against Gen. Garcia. If you weigh the circumstance behind this, was it a justifiable act for the ombudsman to give a plea bargain deal into this case?