UPDATE: Now with video! Here’s the footage of the exchange.
"Two days after Election Day, Chris Christie has crushed his opponent. Is he gonna be the Republican ..." began McGrath.
"The one I feel for is his wife," Matthews cut in.
After a brief pause, some chuckled as McGrath asked, "Why's that?"
"Did you just say, 'crush?'" Matthews said. "I mean, use your imagination."
The crowd erupted.
We'll have video of the exchange a little later on.