I always thought selling reloaded ammunition was a no-no. The maker of the ammunition is responsible for any damages to the person and persons property. Isn't that why it requires an FFL(6 I believe?)? And most likely a pretty good insurance policy?
If he made any profit off of the ammo then the seller is basically producing ammunition without a license and is subject to federal charges. I believe the ATF would highly frown upon hearing someone is producing ammunition without the proper licensing and selling it. I'm sure they would be irritated to hear the ammo is potentially dangerous to the shooter.
The OP stated that the person he did the trade with wasn't the person who reloaded the ammunition. There are vendors at the Indy 1500 who sells reloads. If I purchase a box of reloads from them then turn around and sell it am I committing a crime?