I could sense some possible tell-tale tricks/revealers to that Houdini style stunt:-
(a) Have a woman revealing huge breasts as a good distraction while you arrange something with your hands
(b) Those handcuffs tied to the belt loop....could well be velcro rather than sewn to trousers.
(c) That padded glove he wore to hold the scorpion .... what's the bet that he snapped off the poison sac before he placed it in his mouth? There was no close up shot of the scorpion as it emerged on the plate was there (I was looking to see if the scorpion was in tact but the camera pulled away and those woman were not the brightest to have noticed!)