You are either a Crewmate or Impostor

Ahh, the Airship, where tasks are done, where it was once used by a certain top hat-wearing clan, nothing out of the ordinary, but then you spot an obviously white crewmate(?) strutting around the airship like he owns the ship.

“Heh, don’t mind me, just doing my own tasks and all.”

Do you believe his lie / white lie?