Chamber teleport selling me

I have a mate that mostly plays chambner. I play with him almost on a daily and from time to time it so happens that we peek something together. When there are enemies he often just teleports back and leaves me in the open to fight one or more enemies on my own. He says it makes sense, since they sometimes are focused on him and I should be able to get the, so he says, "free kill". I on the other hand say its stupid cause it might create a situation of me having to fight a 1v1 and if lose that he also has to take another 1v1. This is why I often have to be mad at him, which he says is totally unrightfully. What are you guys saying? Does it make sense of him to TP away, or is he just selling me to the enemies?