You call it a hack, but I call it super useful haha; So many times it saved my ass because when I'm unable to play the game with sound, I can check the log whether the melee attack hit or missed. Well, this specific case is an obscure bug/feature, so I suppose it's not a big deal if it's left as it is.
I don't know much about loftemps and the 3d engine stuff. Could I ask for a short explanation on why the center of the enemy is determined to be voxel (8,8,11)? Or rather, why is the voxel (8,8,11), which should normally be right at the center of the enemy, positioned so low on those screenshots?
Also, normally you'd be able to fire at this enemy, so it's a bit strange that you're not able to melee attack it, despite the majority of its voxels not being obstructed.