3, i don't believe that's legal, i know it's not legal. i went to the site and saw it, someone doesn't know the rules or they cheated(both forgot the one had castled earlier).
it's not legal, but if you can get away with it in a game and it stands, then what can be said? :) not that i would try it, but i think that is what happened in the posted game...
I was looking for the longest practical chess game. I ended up seeing 3 castlings (is that a word?!
) in one game!