[v7.18.3 - ground combat] Undead Mentarch

[SoftwareSimian]

I don't think this is savegame reproducible (therefore I don't have any useful savegame or screenshot to attach), but my soldiers reaction-fire-killed a Mentarch in the UFO but the Mentarch's model kept hovering where it was, tentacles waving in full normal animation, but no longer targetable. Moving to the target square you can see its corpse on the ground, soldiers and aliens can move through that tile, it's just the remove-3D-model-from-world event didn't trigger properly. I remember many months ago this was a problem with sentry guns, never seen it with an alien before but I assume it's the same rare issue.