You keep minimizing his injuries, in addition to his concussion, he had a broken nose and lost two front teeth, not just a bloody lip and chipped tooth you claim:
http://heavy.com/news/2017/04/david-dao-injuries-concussion-video-press-conference-tom-demetrio-doctor-united-airlines-passenger-dragged-removed/
David Dao’s Injuries: Attorney Describes Doctor’s Concussion, Trauma
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According to attorney Tom Demetrio, who is a well-known personal injury attorney in Chicago who has earned millions in verdicts, Dao, 69, suffered the following injuries:
A significant concussion as a result of disembarking the plane.
A “serious broken nose, injury to the sinuses.” He will need reconstructive surgery to repair his broken nose, said Demetrio.
That’s not all, either.
“He lost two front teeth. He’s shaken,” said Demetrio, who said Dao suffered the injuries as he was dragged off the United flight by security, a scene captured in multiple citizen videos that have gone viral on the internet. Demetrio specializes in pain and suffering cases involving airline tragedies and workplace injuries.
“He will have medical treatment for some time,” Demetrio said. He said that Dao’s prognosis was not clear, and he needed to speak to Dao’s doctors still because the injuries are so recent.