Quote Originally Posted by the_mango55
Casualties healed is a feature coming back from MTW.

If you win the battle, then some of your units who were lost during the battle were not killed but just injured enough to take them out of the battle. "casualties healed" represents that, and you get those units back.

Losers don't heal casualties though, I guess because the victor goes around and stabs the bodies to make sure they are dead.
I still play MTW a lot and I never noticed this. What I did notice is that if you win the battle you get your soldiers back that were captured. If you lose, you can ransom back your captured soldiers and lose the soldiers you captured (fleeing and draging along prisoners isn't that easy). AFAIK MTW doesn't make distinctions between dead and wounded.