I agree that I am disgusted by the idea of someone tricking people into doing this for nothing. But if it's a legit contest, I wouldn't mind; it's still creepy, but voluntary and for a possible profit. Is it really any different than enjoying any tv or film tickling clip? I'm sure a few of those were written specifically because the writer or director wanted to see someone tickled.
I did think the only way to access that beta was through ODST(the previous game), but I've just researched a bunch of places that say there are beta codes that let you access before the public beta, what was termed the "friends and family" beta. I don't know if there's codes for the regular beta, too, but there are some kind of codes out there so I won't assume he's lying yet. But at least other contests on youtube show beta footage to prove that the poster has at least one code(any reasonable gamer would have one for themselves before giving them away).