Lawyers for Dao filed an emergency request Wednesday in an IL court seeking to preserve surveillance videos, cockpit voice recordings, passenger and crew lists, and other materials related to United Flight 3411, Reuters reported.
Munoz said the incident on Sunday (Monday NZT) resulted from a "system failure" that prevented employees from using "common sense" in the situation and that Dr David Dao, whom security officers pulled by his hands from the cabin before takeoff, was not at fault.
He said, "No one should ever be mistreated this way".
He added that the feelings of embarrassment were "palpable" for him and his United colleagues.
"This will never happen again", Munoz said during the Wednesday interview with the morning show. "We can't do that".
On Tuesday, Dao told WLKY, a local Kentucky station, that he was still being treated at a Chicago hospital for injuries he suffered in the incident. It is unclear if Dao remains hospitalized.
About 40,000 passengers were involuntarily bumped from flights at the biggest carriers previous year, meaning they were reassigned after the familiar back-and-forth of gate agents calling out voucher amounts and asking for volunteers.
The airline offered passengers up to $800 to give up their seats before it began choosing people to leave, according to other passengers.
In an email to CNN affiliate WBBM, a United spokesperson wrote "All customers on flight 3411 from Sunday, April 9 are receiving compensation for the cost of their tickets".
Kapanen scores double OT winner as Leafs beat Capitals 4-3
Most of all, all the numbers show what your eyes probably told you: the Leafs are going toe-to-toe with a very good hockey team. They're a team that's ferocious on the forecheck and they swarm you when you turn (the puck) over.
Also Wednesday, a Chicago alderman said representatives from United and the city's Aviation Department have been summoned before a city council committee to answer questions about the confrontation at O'Hare Airport.
This news comes after the airline was reported kicking two girls off a flight for wearing leggings last month.
A man dragged off an "overbooked" United Airlines flight in an incident which shocked the world has launched legal action against the passenger carrier.
The incident involving Dao happened Sunday evening in Chicago aboard a plane bound for Louisville.
The company also said all passengers on the flight would be reimbursed for their tickets.
The others complied. After Dao refused, airport security officers yanked him out of his seat and dragged him off the plane. Fellow passengers captured footage of the officers seemingly slamming Dao against an armrest before dragging him along the floor down the aisle and off the plane.
That's when three Aviation Department police officers boarded the plane.
The man dragged from a full United Express flight is a Kentucky physician who was convicted more than a decade ago of felony charges involving his prescribing of drugs. "I don't think our police department should be cooperating with that". "If I'd waited five more minutes, she said, 'That would have been you on TV'".