On the one hand, I'm shocked by their lack of professionalism. On the other had, I hate the constant-fake approach of most newscasters and the genuine laughter is refreshing. Then, there's the simple fact that's it's pretty funny. Overall, I'd let it slide, mostly because I know their are hundreds of over-sensitive types who won't. For that, I feel sorry for the guy.
The best part of watching/experiencing something funny with others, is that their laughing makes me laugh harder. I'm sure you've all gotten the church giggles before.
That's why i wouldn't make it as a news anchor. I see some news segments and say GIVE ME A BREAK! and then there's those that i laugh at really hard.. He made it longer without laughing than i would have.