Hi my friend. This a forum with members/players of the game, not developers. This thing you're saying, is common to see as a "troll" result.
Most of the times it has no logic. You can say that it's a bug of the game. It's usually happens when an opponent (with lower quality)has an injury, he doesn't have auto-subs and he isn't watching the game. Then, for some reason, the program favors this team and there isn't much to do. It can happen few times in a season, to everyone.
Consider this like a simulation of real football, when sometimes everything can happen, forget it and focus in your next games.
It's happening to me 1-2 times every season and I 'm just praying that it will not gonna be in a critical game as semi finals or finals.