Hmmm, well it all seems to be in good fun to me. Just an extension of a lot of other "caught on camera" shows.
To put things into perspective:
I think Japan and the US are similar in of the fact that you can't just record someone and put them up on TV for profit at random. Disclosure agreements and everything else being nessicary.
What this means is that after this happened, the guy doubtlessly agreed that it was funny, and agreed to have it put on TV. He probably got paid a decent sum of money as well, and might even have been sitting on stage (or whatever) when the clip played.
It also means that they tend to carefully research who they are going to "pick on" since they don't want to waste the time and effort going after someone who is going to be all upset afterwards and not let them use the footage. Most reality shows of the type I've seen going so far as to enlist the aid of friends, family, co-workers, etc... to set the victim up at the right time.
So ultimatly asking "do I think this goes too far" I have to firmly say "no". At least not unless your going to argue against all hidden camera shows, which some people do, especially with the current "reality TV" interest.
Now truthfully, I think to some extent Japan is a lot truer to the idea here than we are in the US for the most part. Our reality shows having become jokes and satires of themselves. Largely because of the investment at risk (more than you might think, considering the value of network air time). Safety and not really wanting to push anyone to the edge making them rather predictable, even in cases where they put someone on a reality show with the understanding it's a differant kind of reality show.
Personally I've always wanted to do like a few horror novels, and take the "haunted house" variations to their logical extreme as opposed to cheeze factor. I mean like get someone to sign a contract and then trap them someplace truely freaky for a week or two on camera, especxially if they believe they were on a show but everything went wrong and all the crew members died or disappeared or whatever.
Of course it's not likely to ever happen, and I am generally speaking an evil twit.
