Without going into too much detail, it involed a new mechanic that was made mandatory that he did not appreciate, at all. He threw some rather heated arguments in the style of "Fix, or I quit!". Then the community went on to try and settle the issue, but Machine was VERY upset and eventually quit the forums and deleted everything related to AI War
Two days after, the mechanic was discussed in detail and made optional. So it's definately a very sad day. Machine was one of our most respected members prior to this, so I'm sad to see him go. In spite of how I feel he acted about it all.