It turned out to be a serious bacterial infection. The doctor gave him Cipro ($10 per pill!), told him to wrap his leg in a heating pad 24 hours a day, and told him that if it wasn't getting better in 2 days, they would have to cut open his quads and drain the infection... then they'd have to swab the incision four times per week. Doc said he could have lost his leg if he hadn't come in when he did.
Luckilly, the Cipro took care of the infection. The infection began about 8 hours after the injection. He injected on a Wednesday night and when he woke up, he could hardly walk. It got progressively worse througout the day. He injected 3.5cc of B.A. Labs 100mg/ml test prop.
It is possible that it could have been counterfeit and he was injecting pond water... I looked at the bottle. It was a very watery solution, not like any oil base I've seen. It tasted like test, but I'm not sure whether it was legit.
-Stew