Turret fast firing at nothing

On my most recent jax top game vs singed talon and i were attacking singed in a bush right from my turret. We were low so we backed away and he tried to go under my turret (his minions were there) but was killed by the turret because his poison was damaging us. Then the turret starts firing faster than normal at basicaly nothing. The turret wand lights up and there is sound but nothing comes out of the wand.