Mirvis also tried to soften some of the blows made by Malone earlier in the week, such as his testimony that Diller had refined use of the corporate plane into a "fine art."

Diller said his salary at IAC has never gone about $900,000 and put total compensation, including perks such as the use of the corporate jet, at about $3 million a year.

Abrams, of Wilmington, Delaware's Abrams & Laster, tried to suggest that Diller had taken more than $1.3 billion in stock option gains from IAC as the company's stock tanked. Diller wasn't cooperating. He said he could not, for instance, recite yesterday's closing price of IAC. "I don't track it daily," Diller said.

The Wachtell lawyers objected to the chart used to show the value of the options, created by Daniel Fischel of the economic consulting firm Lexecon. Fischel was hired as an expert who was originally scheduled to testify until the parties agreed to a shortening of the trial. Wachtell first saw the chart at noon yesterday.

Vice Chancellor Stephen Lamb, who is presiding over the case, said there was a "certain unfairness" in the use of the chart, but allowed it.

Diller harrumphed when Abrams referred to $295 million in compensation he made in 2005, saying most of it came from options he exercised at the end of their 10-year period. "Look at it over 10 years if you want to make a real comparison!" Diller said, laughing sarcastically.

Liberty has presented the spinoffs and single-tier stock as Diller's plan to get "hard" control over IAC. On the stand, Diller didn't deny that, but doubted whether he could succeed in getting it.

The spinoffs, he said, were more an effort to allow each business—including Lending Tree and HSN, which runs the Home Shopping Network—to have their own management and get their own valuation in the market, separate from Liberty. "These are fresh little babies," he said. "I want them to be able to have the time to function as public companies."

At the end of the day, Abrams pressed Diller on Malone's history as a persistent investor. When he asked Diller whether he agreed that Maffei is "tenacious," Diller shot back, "I have no comment."

It's clear Diller has no illusion about repairing his relationship with Maffei. In fact, he disputed that they had a relationship, noting that they had met just three times. "Three times and change does not make a relationship," Diller said.

At the last of those meetings, a lunch where Diller arrived on a motor scooter, Maffei made a crack about buses and scooters—a crack that referred to a clause in the proxy that would give voting power back to Liberty in the event of Diller's death or disability.

"I don't really remember," Diller said, his tone exasperated. "It was a joke."

Diller is scheduled to return to the stand on Friday.