My personal preference is that
Rule X is Higurashi's rule Y. Disaster and the murders always happen and when the seagulls cry there are no survivors
Rule Y is the magic that fuels Beatrice or the culprit, Battler's sin, Lambda has touched it sorta.
Rule Z is indefinite, accomplices and group members constantly change, fake deaths, and conspiracies
Personally though I think how the explosion happened isn't all that important. If we speculate on that I think that's one of the things that drowns you in a sea of clues. The fact that the theory about the explosion was confirmed says the explosion did happen. Who did it will be explained later.
Last edited by Judoh; 2010-06-16 at 23:22.