I had similar happen to me. I used T400 for the first time, shot my glute, guy swelled up like a watermelon! Was warm, a little red and softer to the touch than the other glute. Key point being, there was no "bump", it was like an overall enlargement (swelling).
I used a heating pad when I slept, it hurt like hell for about 2 weeks!!
I kept shooting though, after I did the other glute, same thing happened.
I switched to quads, they also hurt, but not as much as the glute, so now I just shoot quads.
If its your buddy's first cycle, I'd say its just a bad case of PIP and irritation.
The only time I'd get really worried is if there's a golf ball size lump, its red, painful and getting bigger day by day. If you're not sure if its getting bigger, draw a circle around it with a marker, then check the next day, if the redness is outside the circle go to the emergency room, you've got an infected abscess.