A 20-year-old Irvine man says he was seeking medical treatment for a brain injury in Rhode Island before he boarded a flight home to California in which he allegedly punched a flight attendant, leading to an emergency landing last week in Denver.

The story of the October 27 assault on American Airlines Flight 976 made national news and it comes after a year of thousands of similar stories in which flight attendants have been made the victims of unruly passengers — most often stemming from pandemic-related mask mandates. In the case of 20-year-old Brian Hsu, however, the conflict appears to have arose when a flight attendant asked Hsu to return to his seat because the fasten-seatbelt sign was on.

The flight was bound from New York's JFK Airport to John Wayne Airport in Orange County, and according to the injured flight attendant and passengers who witnessed the incident, Hsu was standing near an airplane lavatory when the flight attendant told him to step away and return to his seat. As the New York Times reports via court filings, prosecutors say that Hsu then "punched her in the face with sufficient force to cause her to hit the lavatory door."

Another witness said that Hsu struck "her with his fist in a way that appeared practiced or trained."

An earlier account by CBS News claimed that Hsu, a first class passenger, had been himself bumped by the flight attendant, and then approached her in the galley where he allegedly punched her and "returned to his seat as if nothing happened."

The flight attendant then reportedly exclaimed that her nose was broken, and another flight attendant instructed Hsu to return to his seat, where he was restrained with duct tape and zip ties with the help of passengers. The plane then made an emergency landing, and Hsu was detained by authorities there before he was returned to Irvine and arrested at his family's home there.

American Airlines CEO Doug Parker, in a video statement posted to Instagram last week, called the incident "one of the worst displays of unruly behavior we’ve ever witnessed."

Hsu has submitted his own account of the incident to the FBI, and his mother has provided corroborating statements about his condition. Hsu has allegedly suffered from a traumatic head injury he received last year — something for which he says he was being treated in Rhode Island. He reportedly underwent brain surgery in Rhode Island, which involved "reconstructing portions of his skull," and he's reportedly suffered "psychological damage."

According to a statement, Hsu was assaulted while in New York in 2020, which led to the brain injury. Hsu also claimed that a recent "football injury" rendered him unable to make a fist. Hsu apparently is a college student in New York City.

As the East Bay Times reports via the court filings, Hsu's mother told investigators that Hsu "seems to become more easily angered" lately after the injury, and she claimed that he had trouble sitting still and "frequently felt the need to stretch." Also she claimed that her son had been "afraid of people touching his head."

Part of Hsu's account is that the flight attendant "became agitated" after he bumped into her and that she was wildly waving her arms near his head when he struck her in self-defense. He further said he feared that "an impact to his head in its current state could cause him severe injury or death."

Ironically, the flight attendant suffered a concussion from the impact with the lavatory door, and was taken off the plane on a stretcher in Denver.

Hsu appeared in federal court in Santa Ana on Monday, and he was released on $10,000 bond. The judge ordered him not to leave Orange County except to appear in court in Denver later this month to face charges there.

Hsu has been placed on a no-fly list by American Airlines, and he could potentially face 21 years in prison for each of the charges against him.

Top image courtesy of Mackenzie Rose/Twitter