Charlie Sheen’s attacks on the series Two And A Half Men and its executive producer Chuck Lorre, which led to Sheen’s firing last year, were “heartbreaking”, Lorre said today at the Banff World Media Festival. “The guy was my friend and colleague for 8 1/2 years. I don’t think we ever had an argument.” Lorre says he was proud of the show. “For it to end like that was devastating – I don’t know what to say about it other than I was heartbroken and hurt”, he said. What’s more, he and his colleagues didn’t have a firm game plan when they re-launched the show with Ashton Kucher. “There was no development process,” he says. “We actually made all of our mistakes on television….If you watch the 24 shows we did last year, you can watch us stumbling around trying to figure things out. I think we still are, honestly.”

The driving force behind hits including The Big Bang Theory and Mike & Molly says that he works from “a deep sense of insecurity.” If a show is bad then “there’s no reason for the audience to come back….You’re up against the whole universe.” As a result, when one of his sitcoms is recorded “the audience laughs, and if they don’t, we rewrite it or we’ll cut it….There’s a Musollini aspect. The train has to keep going. You never want to call (CBS chief) Les Moonves and say, ‘I have nothing this week’.” Lorre says he learned to keep characters sacrosanct, and not sell them out for a story or a joke. He monitors the tone of a show to be sure that characters have room to grow. In addition to having lots of jokes, scenes have to have a structure. The one-time songwriter — he wrote the theme to Teenage Mutant Ninja Turtles — says that scenes are at lot like well-written music. “At the end, there better be something”, he says.

For all of Deadline's headlines, follow us @Deadline on Twitter.