random damage from azir passive

I played an aram, was playing against an azir. i tried to execute and used mark to dash to master yi right as he died, leaving me without any damage from anyone on their team. then i went to their nexus turrets and died, for azir to then get the kill. confused i looked at the death recap and saw that azir randomly did 5 damage to me with his passive, even tough no turrets were taken down yet. its not a very impactful bug but it is still kinda weird. teams were: >Taric Miss fortune Ahri varus zilean

vs

>urgot master yi azir leona jinx