A note in Pekin Insurance Co.’s claim file about a scaffolding accident that injured Emil Piekutowski nailed down coverage for AAA–1 Masonry & Tuckpointing as an additional insured under a commercial general liability policy that Piekutowski’s employer — Alpha 1 Construction — purchased from Pekin.Piekutowski sued AAA-1 for injuries he suffered on Sept. 20, 2011, when he fell from a suspended platform (called a “swing stage scaffold”) while working on a construction project at …