Master Yi q insta 100% cd reduction

There is a bug I just saw happen in an Aram game. The bug happened when master yi used alpha strike and got a double kills, but his alpha strike then got a 100% cd reduced and was able to alpha strike right away after the kills. he didn't have anything to aa to allow the alpha strike to full reset, he didnt even need anything to auto because he was able to get a 100% cd reduction off the double kill. Lol just wondering but why are people down voting this? Because they are mastery yi mains? I don't play yi because he is a dead brain champion so I wont know things like this