There were 2 incidents. One, Eric Bischoff was apparently on a phone in the office set up he uses for RAW, and Ric Flair walked in and began yelling at Bischoff, citing examples of Bischoff's disrespect towards Flair in WCW. It is, however, unknown what set Flair off to start yelling at Bischoff while he was on the phone. During this, the two faced off and punches were thrown before they were pulled apart.
Two, Ric Flair was sitting at catering and was approached by Bischoff if they could discuss what happened earlier. It ended up becoming another heated argument between the two and they had to be separated once again by backstage agents. Arn was one of the agents at catering to break it up, and eventually, he began getting into it verbally with Bischoff, too. Triple H then came up and helped to calm things down. Arn Anderson, Flair, and Bischoff were then sent to talk to Vince McMahon about the situation.
As of this writing, Ric Flair is still unhappy over what has happened, and no details of the meeting have been released thus yet.
Credit: Dave Scherer @ http://www.1wrestling.com