Depending on the exact circumstances, this may come close to a breach of the Nolan Principle of Integrity. Holders of public office:-
"...should not act or take decisions in order to gain financial or other material benefits for themselves, their family, or their friends."
Were other planning applications fast-tracked, or was this the only one? Without knowing the facts, I'm going to stick my neck out here and predict that the motion before Council wasn't to object to the Chairman's planning application. Would I be right?
My inclination would be to refer this informally to the Monitoring Officer for clarification.
This issue of gagging members of the electorate is fraught with danger and should be used as an absolute last resort. Far too many councils think they have the right to silence their critics, simply for asking the questions they'd rather nobody asked, as Mentorman has indicated.