A statement released to Australia's Fox Sports claims the man at the centre of the incident is an 83-year-old man with a "cognitive impairment".
Figtree Private Hospital - the company that hired the corporate box - said the man was also the father of the woman sitting next to him pictured on the live Fox Sports broadcast.
"Figtree Private Hospital has apologised to the Sydney Kings and the Illawarra Hawks for the actions of an elderly gentleman who was a guest in the hospital's box last evening," hospital chief executive Paul McKenna said in the statement.
"The 83-year-old father of a long-term, valued employee, has some cognitive impairment and does not recall the incident. His family are very regretful of the incident and have indicated they will be making a formal apology on his behalf."
The story made it all the way to the United States with a number of websites reporting how bizarre the entire incident was.
The Kings import was shocked and didn't know how to react before standing up and talking with teammates as umpires worked out what to do.
The man left the arena with his daughter and a beer can in hand after being told to leave by security.
"I saw a little bit," Thornton told Fox Sports after the game. "It's unfortunate, but it is what it is and we move on."
When asked if the spectator should be given a life ban, Thornton said he was happy to leave the decision to the NBL.
"I'm not sure. That's not my call," he said. "I know [the NBL] will take the responsibility. That's their call and that will be that."
The spectator was immediately condemned by NBL fans on social media, many of whom suggested it was a racist act.
- with AAP