A Yahoo vice president wrote that it is "a bizarre outcome if people who stick around make off worse financially than people who [are] laid off."

But another Yahoo executive, using Microsoft's four-letter stock-ticker symbol, noted that the plan "will make things increasingly more expensive for MSFT though."

The "double trigger" plan Yang supported would have first required Microsoft to pay benefits to everyone who lost their jobs as a result of the merger; a second trigger would also require severance for people who were still on the payroll if their jobs changed.

A February 14 email exchange between two Yahoo executives—Gred Mrva, vice president of mergers and acquisitions, and John Dillon, senior director of integration and corporate development—shows them candidly observing they would be better off getting fired under Yahoo.

"You and I will be f***ed as they will find a way to make us work for two more years," Mrva wrote.

Dillon responded by pointing out the double trigger also applied to change of roles. Before a deal could close, he noted, Microsoft would have to ask all remaining employees to waive their right to payment in case their job changed. "And to waive at close, they need to effectively buy us out," Dillon wrote.

The complaint also alleges that Yahoo executives compiled comparative data about similar severance plans from only three other unsolicited takeovers, and in any case never provided the information to any Yahoo director.

Chancellor William Chandler III of the Delaware Chancery Court unsealed the document despite what he said were the "defendants' strenuous arguments" that selective disclosure of the information would prejudice Yahoo at its upcoming proxy contest.

Chandler said the appropriate remedy would be for the release of more information, not less. He encouraged "defendants to release the full text of any communications they believe have been taken out of context or selectively quoted."

For its part, Bernstein Litowitz is pressing ahead with discovery, and will push to depose Yahoo director Arthur Kern, head of the compensation committee.

The lawsuit seeks to invalidate the employee severance plan and ensure that any merger deal maximizes shareholder value.

It also seeks damages if, at the end of the process, Yahoo remains an independent company with a depressed stock price.