The Martial Law Era of Former President Ferdinand Marcos is a complex period in our history. Different kinds of people had different kinds of experiences. Those who took up arms against the state, or were sympathetic to them, naturally had different narratives compared to those who lived through the period as compliant, obedient citizens. And in between are others who had different stories to tell, some positive, some negative, and many others that are mixed. Of course, each side had reasons to stay in theirs, and many, were due to political beliefs. Communism in the Philippines has failed (Had he succeeded in his younger years, Jose Maria Sison would have established something similar to what the Kim family did with North Korea because he believed that he was the Filipino Mao Zedong), but they're trying to actively forward their political agenda on two frontlines: the legal front (the National Democratic Front), and its armed insurgent wing, (the New People's Army). The legal front is mostly dependent on exploiting the people by introducing such concepts to them, most popular is their hiding behind student activism and activism in general, which gave both a bad name and a reputation for being defenders of the communists, and the traitorous sympathisers of the Huks (which is true, for most part now, in modern times). Some were latecomers, and the rest were the originally persuaded by the beliefs.

Many of them didn't believe that communism was the answer to the problems plaguing the Philippines (for the rich, it was obvious why, but for the ones who managed to honestly uplift their socio-economic standing, it was ridiculous, because a lot of them were also people who weren't helped and people who led hard lives, but learned to be dependent on themselves without having to rely on the government too much), and neither was armed struggle, even more. Many had simply done their best in different fields the way the South Koreans did when they experienced their hardships. For students, it was different. Many of them genuinely were sympathisers for the exploited, but for the others, it was different. For all its fearful reputation even at that time, the [Communist] Party [of the Philippines] was merely a ragtag band of hubristic fantasists who thought replicating the Chinese revolution was a cinch.

I can conclude that he definitely wasn't the one behind the Plaza Miranda Incident, or the bombings that followed afterwards. The Plaza Miranda Incident, was confirmed by one of the Party's Founding Fathers, Ruben Guevarra, the Head of the CPP Military Commission and a member of the CPP Central Committee, circa late 60s all the way to the 70s, to have been perpetrated by the Communist Party's very own Dante Cordero, acting with others in the series of bombings, but starting with the Plaza Miranda Incident, otherwise known as Operation Plan Big Leap Forward, the first in a series of campaigns that the CPP launched against the government. Watch the Ideolohiyang Pilipino Dokyu of Sambayanan, in partnership with the UP Diliman Social Sciences Third World Research Department.

You can't find anything completely factual as to official statements released by any officials or opposition at the time because, the tumultuous political atmosphere. Much of anything you can find are either in the form of physical documents, dead people or those who know about it because they were involved in it. Therefore, I don't suggest reading anything from the PRWC official information board [it's heavily biased and contrary to the things I know they did] about things relating to the time, or common google searches for news articles of today. For example, as the of the time of writing this, I'm actually reading on the CIA declassified documents about anything politically-related or anything related to the Philippines at all. It offers a different perspective because they're the third party.