Twisted Treeline countdown bug

Came across this twice tonight. In TT ranked flex, I've waited until the last two seconds to pick my champions, because I'm communicating with my duo partner. Both times I did this, the game immediately boots me whilst having 2s left on the countdown timer. Both times it happened, I had clicked the Lock In button. For reference on Summoner's Rift, the countdown timer will get to 0, stall for a moment, and then boot you.

I have a fairly high end computer (Lenovo Y510P with SLI) and I even turned on low spec mode the second time. If anyone wants to replicate this, be my guest.