To give you the Reader's Digest version, a bunch of college kids got together to eat some soft tacos. 6 of the soft tacos had regular hot sauce added, and 1 of them had Sancto Scorpio added. They filmed a little mini documentary around this little experiment.
If I played Taco Roulette, however, the odds would have to be 50/50. 1 in 7 wouldn't cut it, IMO.