woodja, really?
Since you say you are studying law...what does the law say about intent?
If this individual's goal was to seek asylum, it could have easily been done at the destination, without commiting a serious crime as an excuse.
Taking adverse control of an aircraft in flight, with what intent, I know of a few that drove into structures. As you are aware in law, at the intial stage of the crime, intent is a multi-faceted beast.
If the passengers had stormed the flightdeck, or the air marshal had gained access, and capped the perp, would they be guilty of murder?
There is no excuse, nor any sort of applied (bull****) reasoning that justifies this crime.
The perp stole an aircraft, held hostages against their will