If he is hijacking the plane then he is destroying other people‘s private property.
Yes, but whose? If the government is able to claim the property of criminals because it is illicitly obtained in the first place, then the government official can destroy such property.
People that try to claim right and wrong are not absolute are the ones who tell you the ship is sinking and there is room for five and there’s six of you.
I'm not claiming that.
They also say black and white, not right and wrong so they can say there is a gray area.
Which goes back to an earlier question. Does God have moral authority to kill in judgment? And does He also have authority to give the spoils to others? If God does, does the government?
Someone who hijacks a plane is a hijacker, not a "hijacker". And, if hijacking is
unlawfully seizing (an aircraft, ship, or vehicle) in transit and force it to go to a different destination or use it for one's own purposes, I assume not many people would hesitate to describe hijackers by a phrase such as
"being outside of the proper authority".
Depends on which dictionary you use, but some offer "commandeer" without the "unlawful" part as a definition. As such, it could actually be exactly what I wrote, as commandeer is a term that conveys proper authority.
Hijack b
: to commandeer (a vehicle in transit)
Commandeer:
officially take possession or control of (something), especially for military purposes.