When the plane, which the guards said they had never seen before, was approaching
If'n I lived in ROK and saw a plane I had never seen before approaching from China/generally the north, I'd consider opening fire on it too.
Living in ROK is sort of like living in Israel except there are supposed to be millions of PDRK troops all armed and with tanks, who might or might not have nukyouleer bombs behind them, about like across the street. And them PDRK guys know you have food and TV and stuff that they have not had for a long time. Makes you sort of paranoid, plus all that indoctrination and propoganda and stuff you get fed about how dangerous and nasty, mean and evil the PDRK folks is.
And besides, even if the ROK Marines were out of range shooting at the plane will wake up somebody who might know what's really going on so you do not actually acidentally start WWIII1/2.
The motto of Marines, no matter what country they are in: When it absolutely, positively has to be destroyed overnight. Semper Fi!
stay safe.
