First: Dion should conduct himself in a professional manner at all times. He is paid by us and is supposed to be working FOR us. Second: Omar Alghabra, the minister’s parliamentary secretary for consular affairs, later suggested to reporters that Mr. Dion had let his passion get the better of him but that it was the FAULT of the Conservatives.
It is not the conservatives fault, or the NDP or the Green Party either - Dion is like everyone else on this planet and is responsible for his own actions. He CHOSE to act disrespectfully, he CHOSE to stand by his actions. He CHOSE to carry on in the manner of self entitlement that only the liberals seems to think is justified. 
Dion should apologize, and thank his stars the people of Canada cannot fire him.