Hero dies without attacking strike

During raids, my heroes have been killed whilst I was attacking. There were no ailments against the heroes, and I am positive of this as I kept watch. Why would this happen? It has also resulted in me losing a raid I was winning!

Counter attack is the most likely scenario (Boril, Cyprian, Elena, Obakan on defense)

If it’s something else, any chance you can screen cap or better record the raid to demonstrate the issue?