Deliberate "mistake": Rather than using real Bruce Lee footage only for the final fight scenes so the undisguised Billy Lo's different appearance might make sense after his surgery. The filmmakers instead spliced real Bruce Lee face footage throughout the early film giving the character a constantly changing face from scene to scene.

Continuity: When Billy Lo is fighting the huge guy, he gets a footprint stamped onto his jumpsuit, the print changes size throughout the fight.

Revealing: In the warehouse when Billy kicks one of the black-suited bikers off his bike into the stack of empty tin cans, black wires pulling the bad guy up off the bike and into the cans are visible.