According to our man Anthony Tao at Beijing Cream, a Weibo user (that's Chinese Twitter) said Marbury beat up a fan in the brawl that followed game four of the playoff series between Beijing and Shanxi. Marbury, through his team's general manager, denied the whole thing.
Here's how things started:
The referees were intimidated by Shanxi's fans and gave the game to the home team. They were scared because at least one of them got accosted at close-range by a charging rhinoceros of a surly fuck (1:32 mark in above video), and they were scared because debris rained out of the stands (1:40 mark), causing the Beijing Ducks to huddle around mid-court, where Beijing's Randolph Morris almost got into a fight with one of Shanxi's Chinese players (1:53 mark), while the PA announcer shouted, "Fans, calm down!" Shitstorm? Approaching Category 5.
(Shanxi fans have a reputation of throwing things onto the court when things don't go their way. They did it during both of Marbury's first two games in the CBA two years ago; I was there both times.)
So what did the refs do? They called a phantom foul on Beijing's Morris that gave Shanxi the tie (2:37 mark), then a highly suspect foul on Beijing's Chen Lei that gave Shanxi the win (2:54 mark). But did that appease the masses?
It didn't. Shanxi's fans attacked Beijing's buses and kept them from leaving the stadium for an hour.
And Beijing's general manager says there was no way Marbury could have attacked a fan at any point during the mayhem:
After the game last night, we left the stadium at around 9:40 pm. As the players walked through the players' tunnel to go to the bus, the head coach was standing in the front and Marbury was the last. Next to Marbury was his translator and the players' trainer. When we exited the stadium, there were many fans crowding around outside. They were shouting loudly abusively. When we exited, there were also two security guards who had to help us barricade a path. So when Marbury exited, he had his translator and the two security guards next to him. When he exited, the fans didn't just shout out abuses loudly, but they also threw things at the players, such as stones and water bottles. At that point, our players were just ducking and covering their heads. Under that situation, Marbury couldn't have thrown a punch at a fan, let alone kick continuously.
For his part, the fan posted a doctor's note in which the M.D. recommended two weeks of bed rest.
UPDATE (1:23 p.m.): And now we have video of Marbury responding, at the 1:23 mark: