I have playd aikido tournament and guy names [Pure]Kagenton left a game 30 frames before he lost (Ping out). So i think, ok that is internet issue - thats happens. But he logged 2 second after that and was able to join tournament and tournament was already started...

Of course he was loosing also his next fight and he tried same trick, atleast this time he was not able to join started tournament again.

Those things happen. There's not much that can be done about it, because nobody knows if he did this ping on purpose or if it was accidental. Joining two seconds after is not a problem, as pings delay a lot and players stay for up to 20 seconds after pinging before leaving.