As other guys pointed out already, this tutorial is the WORST idea ever. Using your thumb confuses the hell out of people, because NO ONE expects you to point out something with you THUMB! And almost cupping the woman's breast was the WORST intrusion to someones private space. Touching shoulder?!?! All wrong moves.
You stand one more step back. Show everytnig ON YOUR SELF, with INDEX FINGER. Drop the line from the top AND TURN AROUND while they do it, or have them do it somewhere in secluded room ( bathroom if needed ) . It's best if there is a mirror and asking them to conceal the wire.
When you going to adjust the mic, you will tell them first what exactly you going to do, stand AWAY from them and reach with your arms, not going with your whole body in to their private space.
Who is this guy?!?!