That most definitely is Big Boss, regardless of how you look at it, he was the first incarnation of Big Boss we saw technically, Besides, "I am Big Boss, and you are too."
/
I just read up that sauna thing you mentioned, and it doesn't mention any backs being broken.
Just him commiting "soap play" with someone while her boyfriend saw it, who then fainted and got a month in the infirmary.
On a slightly related note, the blogger lady did that at the summer street market, which is really pretty nice. Kinda surprised she didn't do it at the hippiefest that is they Hyde Park street fair, though