I will say this in French, in order to keep myself in check.
It is totally unacceptable to use the committee as a venue to insult credible people who are here testifying in good faith. It is fine to ask about substance, but when it comes to form, that is something entirely different. When a member goes so far as to question the source of funding, implying that these people may have ulterior motives related to goodness knows what, I think it is incumbent upon the chair to stand up for the witnesses in question. They are here in good faith. Democracy, as I understand it, does not allow for that kind of questioning.