Posts that make fun of dumb arguments are fine, posts that point out critical failures that he could cure are not. Likewise "he he, ha ha, maybe Russ should do [this retarded thing that is very clearly harmful to Null] he he ha ha, wouldn't that be funny?" posts are not allowed because he very well might just do it, and not only harm Null, but also waste his money and time.
Unfortunately, this passes as a highest tier of humor around these parts.
You can naturally say that you think this or that motion won't succeed for this or that reason, without writting a dissertation on the topic (I have been guilty of this myself from time to time). Despite my annoyance with critical posts (and like every second post is some variation of "it's all over, Null should surrender and start selling his anus to Greer"), I don't think I deleted more than a small handful (and I believe I should deleted a fair bit more)