While playing on Livonia official server I encountered the cheater.
After I killed the geared guy I left the village and went to the forest with my friend. While lying in the bushes in the middle of the nowhere I wasn killed with headshot, my friend died in battle with two people.
In ~30 minutes I was looting the military in the area ~few km of my death point. I was lying in the middle of the forest in the bush. I heared the steps and the same 2 guys with our gear appeared and killed me. There's no way to find me in the place I was.
This situation looks like the revenge by using cheats.
I Playing DAYZ SA since 2018, arma mod since 2015 and have never seen something like that. As a game developer myself, I'll appreciate the ban of this person :)