Not amazingly high priority as A. it's a pretty obscure corner case, B. doesn't kill the game and C. has an easy workaround (don't do that), however...

casting Cull the Weak on a unit which has Death Ward gives "interesting" results!

I tactically summoned a Grave Elemental, which effectively gives Death Ward to all units within one tile. Just for the hell of it, I then tried Cull the Weak on one of the Death Ward units. My reasoning was that the damaged unit would die, give me some mana, and then the unit would be immediately resurrected with full hitpoints and full number of troops.

That's sort of what happened, but it was quite weird; the unit showed a death animation, went to zero hitpoints and gave me the mana, and then got stuck. It was then like some ID got mixed up with another unit, because the unit card for the culled/ resurrected unit changed to a completely different picture. The graphic on the tactical map continued to show a dead unit, which was then "resurrected" to show an attacking unit every time the culled/ resurrected unit was involved in a swarm animation, before going back to the dead graphic. If the culled/ resurrected unit is attacked or attacks another unit then the game does seem to eventually sort itself out (you get a full hitpoints resurrected unit again), however in one battle the battle finished before this point, when my culled/ resurrected unit was on zero hitpoints; this unit was considered dead when the battle was over, even though it should have had full hitpoints.

It would be nice if this was fixed (or you could just ban culling units which have had Death Ward cast on them).