His lawyer Paul Smallwood claims it’s not out of the question Marks be handed a fresh sentence involving no jail time.
Marks had only just been released from a psychiatric unit before he boarded the flight and made the ill-advised decision to use ice.
“This is a man who was very, very psychiatrically unwell,” Mr Smallwood told the Court of Appeal on Friday.
Marks was in a different position to someone who had been “boozing on” in the lounge before take-off, he said.
Marks had used drugs before boarding the plane but he was already experiencing residual psychiatric symptoms.
A sentence without jail time was not entirely out of the sentencing range that had been available to County Court Judge Michael McInerney, Mr Smallwood said.
Commonwealth prosecutor Krista Breckweg said the fact Marks did not have a real bomb did not obliterate his moral culpability, but it was lower than if the bomb had been real.
The device turned out to be a bluetooth speaker, but his claims had still deliberately terrified passengers who didn’t know that at the time.
Three judges are hearing the appeal and agreed with the prosecutors position.
The consequences of it being a real bomb would have been “certain death for everyone on that plane” and that would have been terrifying to anyone, Justice Simon Whelan said.
“They are terrorised exactly as if it was a real bomb,” he said.
Ms Breckweg added that a report found the primary cause of the incident was Marks’ meth-induced psychosis.
Passengers and crew restrained Marks onboard the plane during the incident, which occurred shortly after takeoff.
The plane landed within 15 minutes, but it took 40 minutes for security to arrive and passengers had to remain on board for nearly 90 minutes after then.
Marks was in court for the hearing. The judges will hand down their decision at a later date.