Yeah that sounds exactly like the issue on your friend's car.
Obviously the OP would need to check his to see, but clearly the PST UCA could be the problem. The fact that it's the same side as the one your friend had an issue with certainly seems like a lot of coincidence.
If I'm not mistaken, a couple of guys in Kern Dog's thread said there was a bad batch of PST arms that weren't jigged up correctly. I don't know if PST offered replacements or refunds, but that train has set sail.