He may not have gotten anywhere, im not the Owner of the site, Hes busy atm.
We think he may just be entering a code or something as theres no pattern to the wipe and it only happens when hes online :S

Been asked to ask about Non Invasive scripts and low effect deletion ?

Every online gamer forum I have been aware of is php based. Its very common for rival gaming "clans" to attack a forum. Sometimes its just a bored single player. Its almost always one of 2 attacks. An angry former member that had Admin rights to the forum or a SQL injection attack. You dont even need to know much about SQL because there are sites that post the latest injection for php. All the attacker has to do is copy and paste it into the search or login functions and they are in.  A dead give away is if the intruder is making changes that only an admin could make. He doesnt need a script to delete posts, because he is more than likely just doing it manually as an admin.  If thats the case you only have a couple of options.  Make sure you have the latest updated php script or use another forum template that is not as well known as php even if it costs a little.  Of course you might be lucky and grab the IP of the intruder if he is a total noob. If so, you need to document his intrusion with as much as you can put together and make a formal complaint to his ISP.  Oh and yes, IP bans dont work at all because its too easy to use something like TOR to access the site.