What could of this weed been laced with?

My buddy smoked some weed a while ago and had been having panic attacks every night for 3 months. Now some of you might think "He smoked pot, no wonder he had those panic attacks. Because pot is a dangerous drug that makes you retarded." But what you've heard about weed probably isn't true. Anyways, I used to smoke weed a lot and never experienced anxiety or panic attacks so I'm just wondering what it could of been laced with? He said he had a crazy trip looking down at the floor as high as he could look up at the stars. I was thinking PCP, but he said it smelled and tasted good and PCP is supposed to taste like burning rubber and tar. So yeah if you could help me out that'd be great.