A prosecution team investigating a hiring scandal linked to an opposition lawmaker clashed with Prosecutor General Moon Moo-il over the arrest of the lawmaker and indictments of some senior prosecutors.

The trouble surfaced with a press conference held by prosecutor Ahn Mi-hyun of the Uijeongbu District Prosecutors’ Office on Tuesday. She had investigated the case while working at the Chuncheon District Prosecutors’ Office last year.

Ahn revealed that Moon had scolded the chief prosecutor of the Chuncheon district over her plan to summon Rep. Kweon Seong-dong of the opposition Liberty Korea Party in December last year. Ahn claimed the scolding amounted to interference in the investigation and called for a probe into whether Moon exerted undue pressure.

Kweon is suspected of abusing his power to get Kangwon Land, a local casino operator, to hire his former intern illegally in 2013.

A few hours later, the team issued a statement to news media, revealing that Moon temporarily shelved plans to seek an arrest warrant for Kweon and indict the senior prosecutors suspected of having exerted undue pressure on the investigation. The team alleged that Moon broke his promise to guarantee its investigators full independence and took over its investigation.

Moon dismissed the allegations, saying it was the top prosecutor’s duty to manage and supervise prosecutors’ investigations and that he was performing legitimate acts of duty.

Sometimes front-line prosecutors have differed with senior officers in the prosecution, but there was no precedent for prosecutors to hold a news conference and issue a press release to call into question the top prosecutor’s exercise of command and urge an investigation into it.

Such unpredictable behavior is not the only problem. Their arguments are far from convincing.

Ahn defined Moon’s reprimand categorically as interference in the investigation. The team argued Moon broke his promise to guarantee independence.

Moon said he expressed opposition to the summoning of Kweon because of a lack of evidence. The then chief prosecutor of the Chuncheon district said she viewed Moon’s alleged pressure in question as his legitimate exercise of command.

Promising an independent investigation is one thing and advising and instructing along the official lines of command is another.

Though the top prosecutor vowed to ensure independence, the team is undoubtedly an organization within the prosecution.

Even if Moon vowed not to interfere in the investigation, it stands to reason that the top prosecutor should be briefed and so express his opinions.

Under related law, the ultimate responsibility for prosecutors’ investigations lies with prosecutor general. It is beyond question that prosecutors should get approval from the prosecutor general to indict suspects or seek arrest warrants, especially in high-profile cases.

An organization would be abnormal if its front-line members, not its head, were to pass final judgement.

It was reasonable to advise prosecutors take prudence when it comes to whether to arrest Kweon, who chairs the parliamentary judiciary committee, and indict senior officials of the prosecution.

Eventually, Moon approved the team’s plan to seek an arrest warrant for Kweon, but deferred the request until after deciding on whether to indict the senior prosecutors. He advised the team to take professional advice on the indictment issue, and the team accepted the advice. Moon’s position does not sound unfounded.

It is hard to understand why Ahn and the team criticized Moon publicly even when most of its plans were effectively approved.

Moon was censured by liberals late last year after making clear his policy to end investigations into corruption cases of past governments as soon as possible.

Differences can exist between prosecutors who actively pursue President Moon Jae-in’s election pledge to eliminate “evils” and prosecutors not motivated to do so. If some prosecutors’ open criticism of the prosecutor general stems from that point, the prosecution would amount to a political arena.

It is one of prosecutor general’s responsibilities to prevent prosecutors’ abuse of authority to investigate and indict. It is hard to justify the unpredictable and uncontrolled behavior of some prosecutors who seem to view the top prosecutor’s legitimate command as undue interference.

The prosecution needs to tighten its organizational discipline.