There seems to be a serious separation between what is displayed, and what is actually counted. In my cases it has almost always been positive. I lost 4 gold mechs during a fight once, replay said 1. I kept the 3 I should have lost. This happens to me with mechs on daily quests sometimes - I watch it dies, then replay said it didn't.
I also had a fight that I won, and the replay matched what I saw. Then when I watched the replay for the second time, a totally different outcome occurred (and didn't save). In the alternate-reality replay one of my tanks died, that didn't actually, causing his troops to morale boost and kill a lot more things.
From our experiences, this phenomenon appears restricted to mechs.