President Rodrigo Duterte agreed on Wednesday with the observation of opposition Senator Antonio Trillanes IV, his staunch critic, that filing a complaint of usurpation of authority against former President Benigno Aquino III regarding the Mamasapano incident could set a bad precedent.

"You know, that is what life is all about. For the first time or for the second or third time, Trillanes has a good point there," said Duterte, a former prosecutor.

He explained that a president is the commander-in-chief of the Armed Forces of the Philippines and the head of the government.

"The president has the supervision and control. Supervision and control means he can overturn your decision or will decide to exercise the function itself. All those under the appointed officers, all of them under the control," he said.

"In the function of the police, function of the military, the President can always intervene, modify, amend, or change altogether your ideas. And if he decides to do the police work himself, he is the commander-in-chief. He is the head of government insofar as the police is concerned because it is civilian in character," he explained.

He earlier said Aquino, being the president, could tap then suspended Philippine National Police chief Alan Purisima in executing an anti-terrorism operation in January 2015 in Mamasapano, Maguindanao, but unfortunately led to the death of 44 police commandos.

The Ombudsman found probable cause to indict Aquino for usurpation of authority and graft over the Mamasapano incident.

Except for elected local officials whom he could exercise only supervision, the other appointed officials, particularly the Cabinet members are his alter egos or shadows of the president.

"So if the main figure overrules the shadow," he said, there is no usurpation of authority.

"You cannot usurp what is inherently your duty," he explained. Celerina Monte/DMS