That just happened to me today! By the stairs that go near the Beacon, next to the dock. I went into an existing battle cloud, and there was a Technomite and a Pacifier. The Technomite was down, but the Pacifier had no health bar above it, and was still standing there. It did not attack, and we could not attack. The other player eventually fled, and another player came in. We both fled, but the cloud was still there. It was super weird.