[GAMEPLAY] Elixir of sorcery true dame to towers reduced with kog'maw w

On Kog'Maw when you have the effect of elixir of sorcery on and you activate your w the on hit true damage to towers is reduced to 7 per basic attack. Even assuming it is considered as part of his basic attack and subject to the reduced damage which his w causes it should not be reduced by this much. This bug only occurs when Kog'Maw's w is activated and goes back to dealing 25 true damage per basic attack to towers once w wears off.

1. buy elixir of sorcery
2. activate elixir of sorcery
3. activate w
4. attack turret

I've tested this in 2 games, once at level 18 while nearly at the attack speed cap, and once at level 9 with no attack speed items and it happened every time in both games.