(Client) Enemy team has 2 champions selected and you tab out, then can't select.

I had declared as Zac, the enemy team had selected two champions, i tabbed out to check to see if my selection would have been countered. the client froze up and I could not see any champion selections occur. I believe i was on Red.

1. Declare Zac
2. allow enemy team to select two champions
3. Tab out.
4. You will be kicked after a short wait.

Has so far only occured once, and did not change runes but did change masteries. unsure if that had an effect.