"The so-called external pressure claimed by Colonel Park Jung-hoon has not yet been identified and there is no evidence," Presidential Chief of Staff Chung Jin-suk said on July 1. "On the other hand, the case of insubordination has clear substance and evidence." In response, the opposition criticized it as "a guideline for investigation and trial of the president's closest aide."

Chung, who appeared at the National Assembly Steering Committee's presidential office issue inquiry on the same day, responded to a question from the ruling People’s Power Party (PPP) lawmaker Kang Myung-gu who asked for his opinion on the presidential office's external pressure on the investigation into the death of Marine Corporal Chae Su-geun and whether Colonel Park disobeyed. He said, "There are only claims and feelings that I heard through the transmission of messages, but there is no substantial evidence," and added, "Commander Kim Kye-hwan himself, who was said to have communicated with Park, testified that he never said such a thing." As for Park being charged with insubordination, he said, "Park was charged for failing to fulfill the legitimate orders of the minister, his immediate superior."

The opposition protested. "If Chung, who is the president's closest confidant, says that he thinks the case is a crime of mutiny, can he be held accountable for his words?” lawmaker Kang Yoo-jung of the main opposition Democratic Party of Korea (DPK). "Don’t you think it has an influence on the trial?" Kwak Sang-eon of the DPK asked, "How do you know that some things have substance and some things do not even if you do not work for an investigative agency?" Chung replied, "There is no way for me to know the details of Corporal Chae's case only two months after taking office. I have been following it closely for a year and have organized my judgment through the media and messages."

DPK lawmaker Choo Mi-ae said, "The military properly transferred the case (of Corporal Chae's death) to the police according to the law, but the people are asking who ordered the police to retrieve it. Will the police who were illegally retrieved the case properly investigate it?” and asked, "Isn't (Chung's statement) a guideline for investigation?"

Choo also revealed an internal military document that changed the reason for Park's dismissal from "disobeying the minister’s orders" to "disobeying the commander's orders.” It was immediately after Chung said the person Park disobeyed was the "defense minister." She criticized that "They arbitrarily drew a line and changed the minister to the commander," saying, "They changed the document like this and called it insubordination and took personnel measures." She emphasized that the target of the insubordination was not clear.

"If the president does not exercise the right of veto even though it is clearly unconstitutional, it is a dereliction of duty. He should definitely exercise his veto power," Chung said of a special counsel probe bill to investigate the death of Corporal Chae, which has been pursued by the opposition parties. "The Corruption Investigation Office for High-ranking Officials (CIO) itself is a team of permanent special prosecutors, and if a special counsel investigation is launched at a time when the CIO’s investigation is underway, it cannot avoid the shape of a ‘roof on the roof’ where another special counsel investigation is conducted along with the CIO’s investigation.”