Were they partied together? I often see some huge differences in norm games when a new player is partied up with their friend who has lots of experience. When you have a level 5 account playing with a level 100 account and so then the other side ends up with similar crazy stuff going on.
While I do see huge variation on both sides in some games, I do not see that as much if one side is balanced. If one side is all Gold, then usually the other side is pretty balanced as well. I wonder if there is something in the match making that sees when there is a large variation on one team because of parties that it tries to have that same variation on both teams.