When using ritual of destruction on an enemy summon the damage seems to hit the summon being sacrificed. Not sure if this is bound to deploy order.
if you use it on an enemy raven (by ravenspeaker, so originating from your own summons) it DOES do the damage to another champ. It might be owned instead of friendly that are resolved correctly: first destroy, then damage. enemy summon (not from owned): damage, then destroy.