Never attribute to malice what can be explained by "military intelligence". If they're all controlled by remote monitoring from one location, then an engineer can run a loop to change a setting, and it can turn on the wrong setting.

There doesn't seem to be anything indicating an advanced attack. If you're a foreign adversary and you want to flex your muscles (in a way that would be a borderline act of war), you don't just flip one switch and giggle about spoiled food.