In response to the video, United released a statement to KPRC saying it is "disturbed by the completely unacceptable behavior shown in a video of a customer and a former United employee." The employee is no longer with the company, according to the statement.
"The actions shown here do not reflect our core values or our commitment to treat all of our customers with respect and dignity," United's statement read. "We are reviewing all circumstances surrounding this incident and reaching out to our customer through his attorney to profusely apologize for what occurred and to make this right."
The encounter began when Tigner received a boarding pass that was illegible. He made "numerous attempts" to ask for a reprinted pass, but United agents denied him one, according to the lawsuit.
He was told to continue on to the security checkpoint, where Transportation Security Administration authorities refused to let Tigner enter because of his poorly printed pass.
So Tigner went back to the United ticketing area and tried once more to get a new ticket, the lawsuit states. Two United employees, Alejandro Anastasia and Ianthe Phillips-Allred, allegedly refused to help Tigner, laughing and cursing at him, the lawsuit states.
Tigner's attorney, William Hoke, told KPRC that when Tigner asked Anastasia for a new ticket, he replied with a smile, saying, "Can't you see I'm busy?"
Tigner then told Anastasia to "wipe that smile off your face," Hoke said, to which Anastasia responded with an obscenity.
Then, Anastasia "suddenly, unexpectedly and violently injured" Tigner, the lawsuit alleges.
Surveillance video shows the United employee checking his watch, turning toward Tigner and pushing him to the floor. Tigner remains there motionless on his back, his legs and arms spread out. Meanwhile, a couple of people who appear to be airline employees stand near Tigner.
But for about 50 seconds, no one appears to bend down to help Tigner, until a woman - identified by Tigner's lawyer as a flight passenger and nurse - walks over to check on him.
A United employee later called 911, telling the operator, "There's a 70 year old male that had fallen down," according to a 911 call published by KPRC. When the operator asked the employee what caused the fall and if the man was awake, the caller said he did not know.
Anastasia was later charged with a felony of injuring an elderly individual, KPRC reported. He was fined and ordered to attend anger-management classes and apologize to Tigner.
The lawsuit alleges the confrontation caused Tigner to sustain "severe personal injuries and damages," and incur medical expenses and lost wages. It says the altercation left him with "physical disfigurement" and caused him to experience "mental anguish."
It also says that nothing Tigner did or failed to do "caused or contributed to the incident."
The lawsuit follows a number of high-profile controversies involving United, and the airline industry as a whole. In April, Dao refused to give up his seat on an overbooked United flight and was dragged off bloodied and limp, to the disgust of other passengers who captured it on video. Dao suffered a concussion, broken nose and two missing teeth, among other injuries, The Washington Post reported.
Since then, other airlines have come under fire for kicking a family off a flight due to a dispute over a birthday cake and booting a passenger from a plane for using a restroom.
One of the most recent confrontations also involved Houston-based United Airlines agents, who told Yennifer Correia she would have to check her 17th-century violin.
A "wrestling match" ensued, The Post reported, leaving Correia with an injured hand.