McCann moved to Los Angeles in 1979 to become a writer. Distracted by acting for a while, he worked at two separate comedy improv groups— The L.A. Connection and M.D. Sweeney's Acme Comedy Theater (formerly Two Roads Theater; Sweeney has sold the theater, and now runs the restaurant and club next door, said to have been an investment of Acme Alumnus Adam Carolla). Writing comedy skits enabled him to hone his abilities with dialogue and narrative, and to explore the way comic timing is affected by the needs of a story: he was no longer simply throwing out one-liners. He reached the summit of his acting career, he claims, as a double for Duncan Regehr (as Errol Flynn) in My Wicked, Wicked Ways: The Legend of Errol Flynn.
