My understanding, Mr. Proulx, and other committee members, is that the chair actually has a casting vote, so there would be no need at all for another member. My other understanding, quite frankly, is that when the witnesses were testifying, they also testified that they'd never had a situation where they even came close on a vote. They usually find, for the most part, unanimity in relation to most of their votes. So even if there were a disagreement, the chair would have as a prerogative a casting vote to change that. I just don't see the necessity of it.
Evidence of meeting #41 for Transport, Infrastructure and Communities in the 40th Parliament, 2nd Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was ncc.
A recording is available from Parliament.