“McCabe is under the Federal Employees Retirement System. He’s vested. They can’t take that away from him even if he’s fired. “
I think they can for certain felonies.
I don't think that's correct. Pension vesting is a benefit you accrue as part of your job. Being fired, even for cause, doesn't take it away. Being convicted of a crime while you're working might impact it. But being convicted after you retire shouldn't.