Actually the hardest part of flying is the radio and navigating unfamiliar taxi ways. Both require readbacks and a thorough understanding of procedures. Clearance delivery is brutal. One develops a shorthand because the read back must be exact.
That is if you are legal.
Stealing an airplane, one would just ignore ground control, tower, etc. and move on. The tower would shut the airport down for the protection of any inbounds.
The real story here is that if he had managed to start the engines, he would have self destructed on takeoff. Probably run off the far end of the runway at 150 knots or so.
By the way, I have 10,000 hours in light twins, retired from the business that required flying and would be totally unable to fire up a jet engine.
He is a total fool.