I saw this a bit ago. I'd imagine it has something to do with in divorce court the 'retirement' being an asset and paid out to the wife while the pilot 'labors on daily', but I don't know for a fact.
Clearly the pilot that worked out a repayment plan wanted to keep his job and thought this the best means, admit wrong and repay the amount(in the end it was his, but just gotten prior to retirement, and probably with less paid in than would have been at true retirement)