for my 2 cents this happened to my cousin he told me he'd been smokin a couple of years when a dealer offers him this new (at the time)white widow.he buys some goes up to his room starts smokin enjoys the first joint starts on the second all of a sudden he gets the fear and a mad sense of nausea.he told me it was the worse feelin he ever felt and he was convinced he was gonna die to this day has never smoked another joint.
i'm quite a bit older than him and have been smokin for 20 years i've never experienced the fear but if theres one thing you shouldnt do is let someone how admits to "lacing" roll you a joint!he sounds like a right prick!