why are pscavs killing pscavs that kill raiders

istg every time im on reserve ill take out like five raiders when train comes and i let everyone else loot before me because i know no matter what they cant hold it all and yet i always get killed the moment i go to loot, everyone else loots safely and i just get shot in the back while looting i dont understand what a pscav gains from that?? last scav run there was 13 minutes left and train had left, there was a single raider standing there, i shot him, started to loot, then a pscav tried to kill me and eventually did. was he just waiting in the bushes on top of bunker for a pscav to come along and kill that raider? i dont get what he gains from it, if he wanted the loot he couldve killed the raider himself when he was alone there with no one else. do pscavs get karma from killing you if you kill a raider? even then it just seems like bad scav manners. im always willing to split loot i dont know why people just sit there all for you to kill a raider to kill you