The loss of innocence is a gradual process. The longer they stay on the island, the more they forget civilization. This leads to their loss of innocence. All the boys have scene and experienced too much darkness for their age. The killing of the pigs, the sow and finally human is a natural progression of this loss. I have always maintained that the boys' loss of innocence is complete with the death of Simon. With Simon's death the boys have murdered wisdom and goodness. There is no going back to a state of childhood abandon. With Simon's death they have crossed the threshold to where redemption is not possible.

Yes.