"Roy Brouwer, the executive director of the Water Institute and a professor of economics at University of Waterloo, said that the report was a call to action. He added that he does not work with the economic model that GHD used in their methodology and was unfamiliar with it."
The best possible interpretation of this is that Professor Brouwer was asked for an opinion as a person on the street who had the good sense to include a disclaimer: "not my area of expertise as an economics professor".
