He was "happy and proud" that his wife secured the offer before a June 3 meeting of the NBA's owners because he was worried the owners would vote to seize the team, she said.
"Every day we talked about what I was doing .... He was on the same page I was,” she said.
That all changed the next day, when it came time to finalize the sale's details.
"He started screaming and cursing. He was uncontrollable," she said.
Shelly Sterling returned to the witness stand Thursday in the fourth day of a probate hearing that will determine whether she acted legally when she took control of the Sterling Family Trust and sold its NBA team without her husband's approval.
She also testified that her husband had given her permission to sell the team because "he couldn't do it."
"I never thought he would sue me for doing something he asked me to do," she said. "I never, ever thought this would happen."
After the hearing, Pierce O’Donnell, Shelly Sterling’s lawyer, added: “Shelly is the heroine of this story, and Shelly Sterling deserves a lot of gratitude and appreciation for what she did, to step in, to fight her husband, and not to undergo the outrageous slurs from her husband. He’s been proven to be a very sick man, sadly. It’s a tragedy, but Shelly Sterling has shown the world who got $2 billion for the Clippers.”
She also said NBA Commissioner Adam Silver had been willing to negotiate a reduction of her husband's lifetime ban from the NBA to one or two years of probation. But the talks fell apart when Donald refused to put the terms in writing and threatened to sue his fellow owners.
"Do you think the other owners were happy when he called them monsters and was going to find dirt on them?" she said.
Added O’Donnell: “Shelly is trying to get the sale done. She’s doing the right thing. The offer for $2 billion for this team may never come again. The fact of the matter is that she was trying to see if she could work accommodations. There’s no accommodations with Donald Sterling behaving the way he is.”
The courtroom had empty seats Thursday and was much calmer, a noticeable difference from Wednesday's proceedings in which Donald Sterling caused a stir by accusing his wife of lying and calling her a "pig" in court.
Donald Sterling claims he was misled into taking two mental exams at his home that found him to have Alzheimer's disease and gave Shelly Sterling control of the trust.
Judge Michael Levanas said court would not be in session next week to let Donald Sterling's lawyer Max Blecher go on a planned vacation. Closing arguments are scheduled for July 28.
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