The flight attendant who gained attention for being the whistleblower against Korean Air in 2014 is filing a lawsuit against the airline and the airline chairman’s daughter.

Park Chang-jin was chief flight attendant on the now-infamous flight out of New York City’s John F. Kennedy International Airport, on which the airline chairman’s daughter, Cho Hyun-ah, allegedly humiliated the crew after she was served peanuts in a bag instead of on a plate.

Cho was allegedly so angered by the service that she forced the plane to return to the gate at JFK.

The so-called “nut rage” incident earned Cho criticism in both South Korea and abroad. She lost her job and was sentenced to one year in prison in South Korea in 2015 for violating air safety laws. (She served three months.) However, Park says he was also ultimately punished for the incident for his whistleblowing.

After Park took a leave of absence, he came back to his job in May 2017 with a demotion to a regular flight attendant. Park claims that the airline’s reasoning for the demotion was in retaliation for this whistleblowing.

“My case illustrates how those who say no to economic power in South Korea come under a systematic attack from their organization,” Park said at a news conference last week, according to the The New York Times. “I hope my case will help our society to think about the dignity and rights of common workers.”

In the lawsuit, Park claims Cho forced flight attendants to apologize to her on their knees “like slaves in a medieval era,” used abusive language, and threw documents, The New York Times reported. Park's plans to sue were first reported in 2015.

Lee Young-kee, a lawyer who heads the Horuragi Foundation, which works on the behalf of whistleblowers in South Korea, told the New York Times in 2016, “[Government officials and corporate executives] do whatever it takes to find an excuse to expel whistle-blowers.”

“There has been no discrimination or unfairness against him,” Korean Air said in a statement. “We dealt with his case strictly according to our regulations.”