[GAMEPLAY] free visual (Y shotcut) blocked

Hi guys, First of all sorry for my little eng. I was playing a match as Thresh yesterday (http://matchhistory.euw.leagueoflegends.com/en/#match-details/EUW1/1869493683/218158119?tab=overview). In the Team selection i reduce the game to icon for stop my windows media player, next the match started and I was unable to move my view free. I tried to press the Y key a lot of times but nothing happen. I tried to recall but even after recall my visual was still blocked. Next I was slained and after respawn my view start to work normaly. It was the first time i found that bug, after that match I joined one other and this time no problems with my view. Thank for support DeserereX