hallucinogenic reactions.
Having been a stoner for several years (long ago), weed does NOT cause hallucinations! It does however, cause some really stupid thoughts and ideas as well as laziness.
There was a pretty active thread about this story yesterday (one of many?). Interesting stuff about personal experiences and [presumably] atypical reactions.
Well in any case, something made this guy go off. Could have been other substances in his snack, but I think all-things pot-related are going to be convenient pretexts for more big government abuses.