He badly miscalibrated his response. He admitted that he hadn't had time to process the news, which was understandable. But then he said that all he could think of doing was doing what he did best, to make people laugh, and after turning to a different camera, went into his first bit as if nothing had happened.
After a few seconds of shock, I turned the show off.
I have no problem with Noah wanting to do the show he planned. But a host also has to have a feel for the audience. The abruptness of the transition from condolence to comedy was jarring, and felt callous. "Hey, I don't know how to respond to this tragedy, so ... on with the show!"
I'm sorry, but you can't do that.
When Jon Stewart addressed a mass shooting earlier this year, he expressed his sadness and frustration and anger — then went to a commercial break. An ad is a lousy way to change emotional direction, but it's better than going directly to a joke. And when he came back, Stewart made sure to pick up on the same somber note for a moment before almost apologetically carrying on with the show as scripted.
That's how you bring the audience along. Not incidentally, that's also how you avoid looking like an insensitve cretin.
Please don't repeat this mistake, Trevor.
(At least Noah touched on the news. As far as I can tell from quickly switching between them, neither Fallon, Kimmel nor Colbert so much as hinted at it in his opening monologue. I was especially disappointed in Colbert. On the Report he more than once broke character to offer his condolences when tragedy struck. He did so at the beginning of the episode, and made sure to have some kind of bridge, however contrived, to take himself and the audience from the sadness to the comedy.)