Dude Hit His Girlfriend With A Gun And Accidentally Shot Her. Thailand

At least, that's what I think happened. It's from Thailand so there's a good chance I've got it severely lost in translation.
In Nakhon Si Thammarat province, the body of a 27-year-old woman, J.Y., was found in front of a rented house. The corpse was lying prone, with a shot wound with a short-barreled pistol, caliber 9 mm, around her left ear. It appears the bullet penetrated her skull.
The perpetrator was the woman's 30-year-old husband, M.S., who was involved in a drug gang. He was found driving a white Toyota sedan he used to flee the scene. A search revealed he was carrying the murder weapon.
According to a witness, M. had an argument with J. a month prior, causing M. to move to a rented house with three female friends. Eventually, J. found him and had another severe argument. M. tried to get his wife to leave the scene, but she refused, so M. threatened to shoot her. Eventually he decided to pistol-whip her, but on contact the gun went off and shot a bullet, killing J