That 'hands a bit sweaty' affects the outcome way more than you'd think. I've had a seriously unpleasant nip from a mere 24VDC (while drenched in sweat) and only a mild tingle from 90VDC (in an air conditioned office).

In this case I'd guess he's got some decent calluses and any leakage current isn't going through any nerves. Also he's only touching it lightly so won't be making very good contact.