I had a league game where I was just waiting to join and as soon as it was time the game vanished. I checked and it was the 3-0 rule you speak of.

I didn't need the huge win for any practical reason. I am 40+ above the 2nd best goal difference and will crack +100 in league play again. It was annoying because it took goals from my players season and career stats. (which I manually keep track of). For whatever reason my ST's are having a slightly down year from last year and players behind them are getting the benefit. I already have 6 players with 20+ goals and a 7th who scored 10 (3rd ST who started 5 games and played 8 off the bench).