Matchmaking Bug

I just want to bring to light the issue encountered in my last game. Our top laner got destroyed to the point where the poor man went AFK. He was actually trying his best, attempting to counter build his opponent and all, but to no end. After the game I proceed to check his and his opponent's profiles, only to discover that our top laner was Silver IV, while the enemy top laner was Gold IV.

How on Earth is this fair match? The poor dude has NO WAY of going 1vs1 against someone who's a WHOLE tier above him. Can someone explain how this works?