Gabrielle Anwar improvised kicking Michael awake during her audition. It was later added into the shooting script.
When Michael learns that he's been burned, the voice on the other end of the phone call is series creator Matt Nix.
The producers took issue with Bruce Campbell shaving for the role. Bruce had insisted on it due to Sam's constant romancing of wealthy women, but the producers insisted he remain unshaved in order to provide contrast to Jeffrey Donovan's clean-cut leading man look. Consequently Bruce is only clean-shaven in his introductory scene.
When Michael (Jeffrey Donovan) is talking to David (portrayed by Mauricio Suarez) in his apartment about being bullied at school, he shows David his injuries from when he was attacked just after being notified that he'd been burned. He tells David that he holds 2 Black Belts and was still beaten. Jeffrey Donovan in actuality, is a martial artist having studied various styles for over 20 years, focusing on Brazilian Jujitsu for 6 of those years and holds a Black Belt in Karate.
A hurricane-resistant picture window at the restaurant where Sam is meeting with the FBI agents watching Michael shattered from the heat of all the lights being used for the scene.