[LyricalAura]

I don't know that you can safely discard the volcano eruption idea on the grounds that it's too unlikely and coincidental. The mystery couldn't exist without the help of the cat box created by the typhoon and the explosion, so in a sense the fact that Meta Beato "exists" at all fundamentally requires that the cat box be created. It's like a version of the Weak Anthropic Principle, which basically says that "we observe that the universe is in a configuration that supports our existence, even though that configuration is incredibly unlikely, precisely because if it weren't in that configuration, we wouldn't be here to observe it."

We've also seen that, out of the mass of elements we originally attributed to Beatrice, many of them were actually caused by unrelated conspiracies or coincidences, some of which were completely benign. Considering that Beato was apparently trying to get Battler to figure out something more important than the culprit's identity, it would be entirely in keeping with her strategy to make the explosion look like a malevolent act to interfere with his reasoning about motives.

Oh, and don't you think it'd be interesting to have a miraculous event certainly create a perfect cat box?