Error Report #2990 by Mike DeLisa states the following: "Cover was not by Shuster, actually by unknown member of DC staff based on one interior panel. Coloring was not by Jack Adler; Adler states that the work was done by DC staff. My source is the Court record and decision, which includes affidavits from Siegel, Shuster, and Adler."
Superman/Batman #41 indentifies bystander on cover as Rick Radomski of Radomski Hardware. Though this takes place during a dream sequence, the name could be considered canon.