Leave timer

SO this has happened to me a couple of times. I go into queue and sometimes i leave b/c i am mad or i forget to pick. I have noticed that the timer is not true. I always thought that the timer was slow and i checked to see if i was right. After I started the timer i played a 6 MINUTE VIDEO and the timer was only for 5:20. After the video was over it said that only 2 minutes have passed so i hope riot games fixes this because it is really unfair and it is starting to bother me