I saw that too. The guy was Charlie Black, an old GOP hand from the Reagan administration. I have to say Chris was rude to everyone last night, but to Black especially.
IMHO, it was less a matter of rudeness than a continued effort to cover up for the entire legacy of lying, of which Matthews himself is a part.
I would have responsed, "Chris, more than 1 million Vietnamese have immigrated to America since 1975, yet their newspapers are calling Kerry a traitor regarding his VVAW activities. Why is that?"