“Everything you need to know about how to start the engines on an aircraft and get rolling is on YouTube.
And he was cleared to be around aircraft as a baggage handler.”
I am a pilot so I understand that it doesn’t take a whole lot of reading to understand how to start a couple of turbines, but he still should not have had unfettered access to the cockpit. Plus I would think that when the chocks were pulled and the access door closed, it should have alerted someone.
The A/C was on the ramp of a maintenance hangar, not at the gate.