So I'm trying to beat one of the PVE levels, and I'm trying and trying and trying. Finally I break through and by the skin of my teeth I barely eek out a victory. You already know what happens next, the dreaded invalid battle result message

Why does this happen? You already won the battle, your opponent's hero is literally now just ashes. There's a spot on the ground that looks like an explosion where he used to be standing. That seems like a pretty freaking valid battle result to me.

So can you please explain to me a) why does it occasionally give me that invalid battle result after I've already won? And 3) can you please make it stop doing that?

Holy hell that's aggravating.