Client Froze ; Says I Abandoned

Everyone banned. Enemy team first picked Karma. My team hovered Jax and the timer went to 0, then the client visually froze. I typed in chat and others said there was nothing wrong, then after a bit the client reverted to the role selection screen and wouldnt start up or do anything. Rebooted the client and now it says I abandoned a game.

Not upset really, but in case its a common thing here is my complaint. First time it's happened to me.