Board Thread:Questions and Answers/@comment-Misterbunnsy-20130804101027/@comment-Megidra-20130810222410
I don't think he was banned. Geoff makes a passing comment twice; once in the episode after Caleb screen looked and then when the lads saw his house. I think personally he only joins in when he available to. He is now considered apart of achievement hunter team but like lindsay doesn't join in the let's play that much except when he is the mediator between the lads and the creator of another world. I also think similarly to how the belt is just between the 6, the tower is the same, so Caleb sort has to earn his "place".
Just my 2 cent.