UPDATE (12 a.m. ET): A wild day of reports that has revolved around a bidding war over the Clippers took a strange twist late Thursday night, as ESPN reported that embattled owner Donald Sterling's mental state could ultimately render any effort to retain the franchise moot.

According to the report, the 80-year-old Sterling was recently found to be incapacitated by experts — a diagnosis which gives estranged wife Shelly Sterling the sole authority to negotiate the sale of the club under guidelines of the Sterling family trust, which is the legal owner of the franchise.

This would explain the breakneck pace at which the bidding for the team escalated on Thursday, with multiple reports indicating that Shelly Sterling reached an agreement with former Microsoft CEO Steve Ballmer to sell the Clippers for $2 billion.

ESPN reported late Thursday that not only was an agreement in place, but that an agreement had been signed by the trust and sent to the NBA for final approval.

Also on Thursday, Los Angeles Times reporter Andrea Chang live-tweeted from the Sterling family residence, in the process getting plenty of comments from a man she reported to be Donald Sterling's attorney. The attorney indicated Donald Sterling's insistence that he will do whatever he can to stop any sale of the Clippers.

Among the statements Chang got:

Even if the reports of the signed agreement pan out, it does not mean a sale is final. As of Thursday night, the Los Angeles Times would not go as far as ESPN with respect to whether Donald Sterling would need to sign off on a deal to make it final:

Donald Sterling has equivocated on whether he would sign off on a sale of the Clippers. Another of his attorneys, Maxwell Blecher, said Donald Sterling wanted "vindication" more than a high sale price.

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Maybe Steve Ballmer submitted the winning bid for the Los Angeles Clippers or maybe he didn't, but one thing is clear — $2 billion would be a lot of money to pay for an NBA franchise.

Conflicting reports emerged Thursday about the ex-Microsoft CEO, with the Los Angeles Times saying Ballmer appeared to have won the bidding war for Donald Sterling's team with a $2 billion offer that trumped those of other major players:

The Geffen group offered $1.6 billion and the Ressler-Karsh group $1.2 billion. People familiar with both those offers said they were rejected.

ESPN.com seemed to confirm later, saying that sources told the site that the Sterling family trust has reached a deal with Ballmer.

The Associated Press reported later that Ballmer had reached a "binding agreement" to buy the team with Shelly Sterling.

The NBA still needs to approve the sale, and it's still unclear how much Donald Sterling -- who still legally owns the team -- intends to get involved in this, if at all.

Sterling's attorney, Bobby Samini, made some comments Thursday, according to the LA Times, that seem to indicate a desire to be very much involved. "There's been no sale," Samini said, according to the Times. "There can be no sale without Donald's signature."

But the ESPN.com report, citing sources, claims that Sterling's approval isn't needed and that the agreement between the family trust and Ballmer will go immediately to the NBA for final approval.

That conflicts with the LA Times' reporting, which said the tentative deal still must receive the blessing of Donald Sterling, who has waxed and waned on the question of whether he would allow his wife to sell the team he has controlled for more than three decades.

The deal also needs the eventual approval of three-fourths of the 29 other NBA owners, but is expected to clear that hurdle as long as Ballmer reaffirms his pledge to keep the team in Los Angeles and not move it to the Seattle srea, where he lives.

What we do know? $2 billion would be more than anyone has ever paid for an NBA franchise by almost a factor of four. The Milwaukee Bucks were recently purchased for a record $550 million.