Yeah, and that's why I pretty much stopped tagging suspected bounty cheaters based on address linkage. There's too much uncertainty in my mind, though I'm about 90% sure that individual bounty participants don't really pool funds for whatever reason they give once they get caught.
I also very rarely link addresses, realizing that it is difficult to prove, but not in this case. If you take a deeper look, then if they were separate different personalities, there would be no such order in their actions. In addition, I know that this is definitely one person, as I checked his activities very carefully and even contacted PM