One of those situations I actively tried to avoid as a DM:
The fight against the orc tribe was long and hard. Especially the king and his bodyguards were tough opponents. But now our good aligned group of heroes (including one paladin and one ranger) has made it to the last chamber of the cave-complex. Here they find the women and children of the orcs huddled together.
The women and some of the older children detect weekly as evil while the babies and most of the children seem to be innocent.
What would you do in place of the PCs?