SERIOUS problem with Rek'Sai

If the enemy team has seen your tunnel (so it is on their minimap and in their fog of war), and you ult to it while they have no vision of it, they see the purple rocks above the tunnel that signal you're going there. It doesn't make much sense considering they can only see it in the fog of war. Makes her ult unusable for ganking if they've seen your tunnel but haven't cleared it yet.