You did have this one juicy nugget - Edit 1
Before modification by Lord o' Salv at 12/11/2009 02:55:02 AM
Brandon hinted at some severe limitations on Shaidar Haran to affect the physical world. He says that a lot of actions that people assume to be those of Shaidar Haran in the book in one particular scene were physically carried out by Elza. He further indicated that Shadar Haran would have been incapable of physically placing the collar himself.
This may well clear up questions on that scene, and definitely helps my understand of Shaidar Haran. He seemed far too powerful before this quote.