EDIT corroboration with block withholders Slush never came out with the type of miners and software being used to attack the pool in which he stated he had communication with the attackers. In which many miners lost btc since it went on for months! Check his blog posts. That alone .. withholding crucial info from the community makes him anything but legitimate!
IIRC he did say that it was custom software, which suggests to me that any such information would be totally irrelevant.
Well thats not for you to decide is it.. Its relevant for some and that should be enough
My bullshit detector says it is just that and he doesn't want to be liable for the loses incurred due to being a shit pool OP
Best Regards