4v5 Ranked Games

I've had this thought many times, and shared it with those I play with. But, it has never bothered me much until tonight. I was playing my third game in my series promotion matches and our top laner never connected to the game so it was a 4v5 the entire game. I play jungle, so I couldn't gank and cover the top lane simultaneously, and therefor we lost.

I strongly believe that myself and my teammates who remained in the game should get credited with a loss in series or a loss of LP. Why punish those who connected to the game, but were given a severe disadvantage because of one other player?

My solution would be to give the AFK player a loss, with appropriate loss of LP, and give the teammates of the disconnected player a tie, of sorts (no loss of LP, and not counted at a win or loss in series). Those on the other team had no influence or effect on the game, other than a free win. So that shouldn't be changed. But, the players on the team of a disconnected player should not get punished for their disconnected teammates fault.