Jhin's Fourth Shot interaction with Mordekaiser ult

In a game I recently played, I was ulted by a Mordekaiser and I had died. My ghost was used by him and after he expended three shots, the fourth shot would always activate. There would be no reloading of Jhin's clip and every auto attack at that point toggled Jhins enhanced fourth shot for every auto attack he performed. This means the % execute damage and critical strike was guaranteed for every auto attacks so long as the ghost lived.