P-F-T??
Is your friend going to have the money rebated and also receive a paycheck? If this is the case, it may be some sort of training contract arrangement or some kind of a bond.
Some places will make you sign training and/or employment contracts, in which you promise to work for a specified period. If you leave before the time is up, you'll be liable for the company's cost to train you, probably on a prorated basis. I had to sign such a contract at FSI. It was unexpected, but I had no problem with it. I was not asked for money. The contract was for a 15-month term. I left after 13, and not a word was said about breach or anything like it.
If your friend is only getting the $5K rebated in increments and his "pay" is coming out of the money he put up, that sounds like P-F-T, and work-for-free to me. Moreover, the company will deduct Social Security and withholding from those monies, and your friend won't get his full $5K back. That sounds like fraud to me.
You have to decide for yourself if you want to sign an employment or training contract. Personally, I would have had no qualms about signing a training contract. Of course, P-F-T is P-F-T and everything that it implies.