Insurance companies tend to be a bit conservative, and lag behind the times. But, as my gas company kept telling me, gas explodes, it's really really dangerous. (They kept warning me about pilot lights I might have, for things like a gas refrigerator, too. Ah, not in this town, not for fifty years or more.)
There's such a thing as being too conservative, too. Unless your insurnace policy was cleverly enough written to ban flash heaters, that's the kind of question you might just not want to bring up next time around.