The most common hypothesis is that a Legendary Pokemon is involved somehow, though that seems to be the defeat reaction to anything that cannot immediately be explained.

[Of course deities of some sort are the only possibility when you can't explain something. How ridiculous.]

Honestly, people need to stop being so impatient and actually work for a proper solution.

[He sighs angrily.]

But I digress. What particular theories do you have in mind? It would be useful to compare notes in a case like this.