The lawyer for United passenger David Dao said his client suffered "a significant concussion" a "serious broken nose, injury to sinuses and he is going to be undergoing shortly reconstructive surgery." (Reuters)

The attorney representing the man who was dragged off a United Airlines flight Sunday said it’s likely his client will sue the company.

“Will there be a lawsuit? Yeah, probably,” Thomas Demetrio, one of the attorneys representing David Dao, said at a Thursday morning news conference in Chicago.

Demetrio said “unreasonable force and violence” were used against his client.

“I would defy anyone to suggest there was not unreasonable force and violence used to help Dr. Dao disembark that plane,” he said.

Dao’s daughter, Crystal Pepper, said the family was “horrified and shocked” at seeing the video of the incident.

Dao was discharged from the hospital late Wednesday night and suffered a serious concussion and broken nose, his attorney said. Demetrio said Dao also lost two front teeth and will undergo reconstructive surgery.

The news conference comes one day after United chief Oscar Munoz publicly apologized to for the incident and said he felt “shame” after viewing the video. Asked what he thought of Munoz’s apology, Demetrio said it sounded “staged.” He said neither he nor Dao had heard from anyone at United. He added later that the family did accept Munoz’s televised apology “with gratitude.”

“If you’re going to eject a passenger, under no circumstances can it be done with unreasonable force or violence. … That’s the law,” Demetrio said, adding that he has heard from hundreds of travelers about their experiences.

He said he has concluded that “for far too long airlines, United in particular, have bullied passengers.” He said Dao, 69, intends to use his case to advocate for all passengers.

“Dr. Dao understands he’s the guy to stand up for passengers, going forward,” Demetrio said.

On Wednesday, attorneys filed an emergency bill of discovery in Cook County Circuit Court asking the court to order United and the City of Chicago preserve items linked to Sunday’s incident, including video footage of the boarding process, a passenger list and cockpit voice recordings from the flight.

Later Thursday, representatives from United are expected to appear at a hearing on the incident before the Chicago City Council’s aviation committee.

Three aviation security officers have been suspended in connection with the incident that took place Sunday at Chicago’s O’Hare airport. And the airline has promised full refunds to the passengers on the flight.

Videos showed Dao, a passenger on a Louisville-bound flight, being dragged out of his seat after he refused to leave the plane to make room for crew members who needed seats on the flight. Passengers are overheard saying “Oh, my God,” as Dao is dragged down the aisle. The video then picks up a few minutes later showing Dao, his face is bloody and his clothing mussed.

The Rev. Jesse Jackson, center, stages a protest against United Airlines at Chicago’s O’Hare International Airport on April 12. The protest was in response to airport police physically removing passenger David Dao from his seat and dragging him off the airplane. (Joshua Lott/AFP/Getty Images)

The incident sparked outrage and protests, including one held at O’Hare Thursday featuring the Rev. Jesse Jackson. The airline’s stock price dropped, and there have been calls for boycotts from as far away as China, where the story has stirred outrage because Dao is Asian. Dao’s daughter said Thursday that her father is a Vietnamese immigrant.

Demetrio said Dao told him the dragging incident was more horrifying than when he fled Vietnam.

United officials said that race was in no way a consideration when they chose who would be removed from a flight. But they have not said how the four passengers removed from the flight were chosen.

Airlines uses a variety of criteria to determine whom to bump from flights, including the price passengers paid for their tickets and their check-in time.

After initially appearing to place blame on Dao for being “belligerent” and refusing to give up his seat, Munoz appeared on national television Wednesday and said he felt “shame” when he saw the video.

When asked if Dao was at fault for the actions that led to his removal from the plane as it sat on the runway Sunday at Chicago’s O’Hare International Airport, Munoz said, simply: “No, he cannot be. He was a paying passenger sitting in his seat on our aircraft. No one should be treated that way.”

Munoz, who said there will be a full investigation into the incident, and signaled that there will be changes in the relationship between the airline and local law enforcement officers who are called to handle passenger issues on flights. He said results of the investigation will be released by the end of the month.

The situation has focused attention on airlines’ practice of overbooking, in which they sell more tickets than seats to compensate for travelers who don’t show up for their flights.  Such a practice is not illegal but can lead to conflict if there is a mismatch between passengers and seats.

On Wednesday, New Jersey Gov. Chris Christie (R) called on the Trump administration to halt the practice until new guidelines are put into place. Sen. Chris Van Hollen (D-Md.) announced that he is seeking support for the Customers Not Cargo Act, which would prohibit airlines from forcibly removing passengers after they have already boarded the plane because of overbooking or airline staff seeking to fly as passengers.