Bug Client really annoying

The bug is pretty simple. My friend join a game and he is in the champion select and when he lock his champion, his client just completely freeze and he can't dodge the game to lose 2 LP so we remake and he lose about 20 LP each time. He can fix this problem by closing his computer but it take like 8 minutes to come back in game but in this time, the destiny of game is pretty already chosen and we take a loss. He already looses 40 LP because of that and we hope that this bug will be fixed