Bob Woodward is leaving the regular payroll of the Washington Post, along with about 100 other Posties who are accepting the paper’s generous early retirement package.

For the Post’s legendary investigative reporter, however, the buyout may not exactly yield a windfall, largely because he has been drawing a salary of $10,000 for the past couple of years.

The buyout gives the most senior Post staffers an exit payment of two times their final salary. On that basis, Woodward would get a check for $20,000, or enough for a 2008 Chrysler Sebring. He is 65 and started at the Post in 1971.

Yet there’s an interesting wrinkle in Woodward’s package: That $10,000 salary? It represents a voluntary pay cut that took effect in mid-2006. Prior to that, Woodward earned a salary commensurate with his title as a Post assistant managing editor, about $180,000. If his exit payment is calculated on that basis, he’d get $360,000 via the buyout.

The biz people at the paper are now trying to figure out whether to give Woodward the small payout or the large payout.

It all makes for a compelling case study in corporate ethics. Here’s why: The current round of Post buyouts is the third that Woodward has evaluated this decade. He was tempted by the previous offer, which offered similar inducements and came across his desk in 2006.

But he was convinced by Post management to stick around, and so passed up the big payday. And what a payday it would have been. First, Woodward would have gotten a $360,000 lump-sum payment, and over the past two years he would have raked in $160,000 in retirement payouts.

But instead of taking that early retirement plan, Woodward insisted on a pay cut.

Two years later, along comes a brand new buyout package, which may well be the last such opportunity for Post veterans. If the company goes with a strict calculation of his salary, he’ll go home with the $20,000 and will have lost about a half-million dollars.

This guy, of course, will put food on the table either way. Best-selling books finance a comfortable life for Woodward, a longtime Georgetown resident who is currently at work on his fourth tome about George W. Bush’s war in Iraq. Other volumes in this series—Bush at War, Plan of Attack, and State of Denial: Bush at War, Part III—have sold millions of copies.

As long ago as the ‘90s, Woodward asked his bosses at the paper to reduce his salary to $1 a year. They declined to make any such drastic adjustment—until after Craigslist and a prolonged advertising slump had shredded the paper’s profitability.

Outside of the bizarre numbers, Woodward’s technical change in status is about the least newsworthy of all the recent personnel changes at the Post. That’s because he’ll be under contract to continue in his capacity as one of the paper’s at-large assets, available to contribute reporting for big stories—like the 9/11 coverage—and give the Post the first whack at excerpts of his books. “We wanted Bob to maintain a relationship with the paper, forever,” says Executive Editor Leonard Downie Jr., noting that Woodward “will continue doing exactly what he’s been doing.”

It’s safe to say that the contract will be among the paper’s cheapest. Woodward is asking for $1 a year. “He’s a self-effacing guy,” says Downie.