I would say that it's not an act of war against Samsung but South Korea which should be a difference.
Insurance policies have often tried to exclude the highly-unlikely-but-ruiniously-costly coverage; hence the similar "acts of god" exclusions (and obvs there's rarely any disagreement about whether god was specifically the actor). A war is a usually a large-scale event causing a large amount of damage; without excluding it you would expect many insurers to be bankrupted. "Cyberwar" is something of a different matter and I could see why either side would want to litigate to clarify the definition.