Steps to reproduce:
1. Save game with enemies visible & toggle tooltips on
2. Engage enemies, hit them a bit, and then load the game
3. View the enemies that still seem to be "Badly Injured" etc. even though you just loaded the game.
It might be a display issue, but I can see them regenerating so maybe not. I've not tested if this actually persists in combat, either, as I have a desire to not cheese the game too much.
If it doesn't happen with all enemies, I specifically notice it with the forest lurkers in the corner of the black garden (forget name, path to Caed Nua)