I am not sure what this was, but today when I did this, there were several injured and barely injured enemies inside already. Maybe someone had started the quest and not finished it, and it did not reset properly after that? There were also those that were uninjured.

I could take the quest, and finish it normally.

I saw this once on the gnoll quest. I thought it might be the difficulty scaling since we had a small, lower level party at the time.

This may have been my fault, I was using some Caltrops in there earlier today, and there were some remaining when I left.

That would explain it. I'll quit trying to reproduce the bug.