Shit I shot test prop for 10 weeks eod and every one was so fucking sore and stuck out. i would rotate left shoulder, right shoulder, left glute, right glute, left quad, right quad...and by the time i got back to do the same spot again, sometimes it would still be tender. that's like 10 days beteen sites!
Since your friend is ok...assume that it's pretty clean stuff...some people are just prone to have a reaction. If you have to discontinue the stuff...try a different brand...I have shopped around until I found the best in results, prices, and least amount of pain.