"Well, we will have to drag you", the officer says in the video.
"The key is managing it before you get to the boarding process", Bastian said.
Compelling ticketed passengers to give up a seat can be costly, and as United has learned, damaging to an airline's reputation and share price.
USA airlines are bumping passengers off flights at the lowest rate since 1995, a Reuters analysis of federal data showed on Tuesday, even as United Continental Holdings (UAL) has kicked up a storm over the practice. He said that plane seats are perishable commodities - once the door has been closed, seats on a flight can't be sold and lose all value.
Delta in 2016 had 1,200 denied boardings for the entire year, or one in 100,000 passengers.
Bumping is not limited to flights that are oversold. It can happen if the plane is overweight or air marshals need a seat.
Munoz promised a full review by April 30 "to fix what's broken so this never happens again".
In this case, United needed to make room for a flight crew and called security personnel when no passengers volunteered to give up their seat.
Airport police officers called to remove a passenger who refused to leave a United Express flight essentially walked into what law enforcement experts say was a no-win situation: enforcing a business decision by a private company. He described the man as "disruptive and belligerent".
Politicians have jumped on the public outrage.
On Wednesday, 21 Senate Democrats demanded a more-detailed account of the incident from Munoz.
"T$3 he use of law enforcement onboard an aircraft has to be looked at very carefully", Munoz said, before acknowledging that they are usually there for the goal of safety.
But once police were aboard the plane, it would have been hard to walk away, especially if they did not know why the passenger was asked to leave, said Kevin Murphy, executive director of the Airport Law Enforcement Agencies Network.
Sen. Richard Blumenthal, D-Conn., asked the U.S. Department of Transportation to analyze "the problem of overbooking passengers throughout the industry". He said was working on legislation to increase passengers' rights.
"The family of Dr. Dao wants the world to know that they are very appreciative of the outpouring of prayers, concern and support they have received", Dao's lawyer said, according to WLKY. "You have an obligation", Murphy said. It is unconscionable behavior on the part of United's employees, not to mention the time, indignity and inconvenience that the passengers could have been spared by more thoughtful and considerate employees.
Hawaiian Airlines (HA), a relatively small carrier, fares best on both measures. United acknowledged that passengers may have been less willing to listen to offers once they were seated on the plane.
United spokeswoman Megan McCarthy said on Wednesday that the passengers can take the compensation in cash, travel credits or miles.