Gustin was on a first-class flight carrying 68 people to Vancouver.
He allegedly went into the bathroom to have a vape break.
Vaping in the enclosed space caused what apparently looked like smoke to pour out of the bathroom, setting off an alarm and forcing the pilots to wear oxygen masks.
Flight attendants confiscated the vape pen without any incident.
Gustin was held back on the plane upon landing in order to speak with authorities.
He was reportedly let off with only a warning.