How ever I do understand the point here, together with Kuwabara's well exicuted mind fuck, and having read some of the real life rules for Go playing at tournaments (= full of nitpicking rules and too obvious for words rules), that such mindfucks happen in competitive Go.

At least Sai strongly disaproved, but he was not fast enough to be of any help here.
IMHO Sai's too passive, throughout the entire Manga.