I'm sorry that happened to you. This game lacks logic way too often!
Two things to watch for tactically, during the match.
As toxcatl stated, the match statistics screen is all screwy. If you don't logout of your match, and then rejoin your stats will frequently be behind. That isn't your fault though, any new manager isn't going to know that initially and it's really a shame their is a lag on accurate match statistics.
Also, your opponent may have changed something tactically that caused the match to swing into their favor late. This can be spotted in the match ratings. If you're rating are all good, and been in the green all match, then suddenly they go bright red for several players at once, it's evidence your opponent changed something, and the algorithm isn't in your favor anymore. Same applies if you make a change, and the next ratings are all red. Just hopefully, we as managers are able to spot the change and make the necessary adjustment before we concede a goal.