Walking through first Carousel wall

Essentially if you alt tab then tab back into the game and click within the first carousel before the game starts to move you you will end up walking through the wall and be able to pick a champ before anyone else can. I was on borderless and when I alt tabbed back into the game from my second screen it let me do this I dont know if any of those things will have an effect. TLDR unfair first pick because alt tab.