Why do people disconnect the moment they die?

Okay so it’s happened a few time now but this most recent one was so confusing to me, we were in the huller and we were fighting another group, one of our member was downed and then I was, medic picked me up with ult and we pushed to take down the enemy. We beat the enemy team and I went to pick up the other guy, I got to him just as his revive depleted and boom he left the game. Like he had a mission in the huller that we didn’t do and I would have been able to pick him up in like 20 seconds. I was just left there wondering why he left. He would have seen the enemy were dead and it was just us in there.