Erik, the letter to Wrights was from the Secretary, not the Treasurer. Bylaw 7.6 says “The Secretary shall be the recording officer of the Party” and shall “keep such minutes and records as necessary”.
I don't claim that the rules here are clear. The possibility of unclear rules is why a body has one Chair -- no more, no less. A fundamental problem in institutional design here is how to reconcile two opposing and seemingly unlimited powers -- the ability of a bare majority to overturn a ruling of the Chair, and the ability of the Chair to declare that a ruling is not subject to appeal. It seems that Robert's must choose either the potential tyranny of the majority, or the potential tyranny of the one.
Robert's comes down squarely on the side of the latter: "By electing a presiding officer, the assembly delegates to him the authority and duty to make necessary rulings on questions of parliamentary law." (p. 247) "When the chair rules on a question about which there cannot possibly be two reasonable opinions, an appeal would be dilatory and is not allowed." (p. 248) I guess the theory is that it's easier for a principled majority to reign in a tyrannical Chair, than for a principled Chair to reign in a tyrannical majority. Also, the majority ultimately has only itself to blame if it elects a tyrant as Chair.
In spite of all the abuse that a few people have heaped on him, Bill Redpath has been very fair in all the contexts that I've seen him operating.