BUG Ekko V Kog Maw

If Ekko has an ability active i.e. his q is out waiting to return, his w is waiting to activate, he is inbetween the dash and the blink on the E... Kog'Maw's E does not do dmg. It will still proc the slow but there is no dmg. For example he decided to dive me, I slowed him but it didnt do any dmg and he took a few turret shots so he used his ult to get out. 30 seconds later he decided to dive me again and he killed me but I got my E of and it slowed him so he ended up taking two turret shots and died... EXECUTED............