Yes, although in this case if he made the decision he did and people didn't like it, there were enough people who knew. I assume somebody at the Treasury Board would have had something to say and ministers would have had something to say. It's perhaps overly simplistic, but I agree that in the end the deputy minister is the one who first decides whether or not to recommend the supplementary estimates.
On June 8th, 2006. See this statement in context.