I assumed he would anyway. As a federal employee all he has to do is work a few more days at a federal agency to meet his goal. Isn't that how it works?
Generally, yes, though if a run of the mill gov worker were fired (actually fired) a few days before full retirement, good luck getting a deal like this. Also, depending on the retirement plan he's on, it's not like this is an "all or nothing" deal. He might not be getting all his retirement, but he'll be getting some, maybe most of it. If they're talking about "a few days" before a full retirement date, the biggest thing I could see affected would be keeping his health insurance.
Also, feds can use acquired sick leave as time in service, so if he only has a few days, doesn't the guy have any sick leave saved up? Though there could be other rules for fed LE.