invading enemy taking no damage.

was just invaded on day 4 by a HUGE force i had 4 villagers and they rushed in with 9 i had no defenses set up so i was already screwed, i took control of my leader who had 4++ mele and went in to battle( because doing this makes it way easier to win even out numbered), every time i or my villagers would hit after a certain point of hp the whole enemy team stopped taking damage period. id just hear the chink chink sound of armor like i was hitting but did 0 damage eventually they just killed all but one of my people and ran off with my leader.