How about this:

Most folks on the mat are altered in some way or another -- pharmaceutically, "para"-pharmaceutically and otherwise. We aikido folks are all a bit whacky.

I'd say that stuff like the neophyte's fear, the inflated egos of way too many senior students, the parochialism and attendant crappy mental hygeine (not to mention crappy technique) in many dojo all pose similar dangers to those posed by a stoned student or instructor.