They started shooting The Smiling Man on actress Abby's 6th birthday. The state of California's film laws only allow children under 6 years of age to be on set for 4 hours a day; so Abby's Mother suggested that they wait to start filming on Abby's birthday, which they did.
There is no dialog in the film, only voice effects; yet there is a specific section for voice actors in the cast. Strange Dave is listed in the acting cast as the Smiling Man, then is listed, along with Richard Dorton, as the voice actor for the Smiling Man.