Still, implicating other countries so soon seems premature and reactonary to me. Its like corporate news jumping to 'terrorism' immediately after any domestic tragedy. Our threat models need to include more than just nation states. Otherwise, we end up contributing to escalation through untethered fear.
It doesn't mean you stop looking for causes or eliminate human error though.
The viability of Russia/NK depends on how the EAS network is set up in Hawaii. If they have internet-facing servers, it's completely possible.