OK, going off-topic... Under the hypothetical situation that a time machine could be built and that you could travel back to the time before your mother's birth, it would still be impossible for you to kill your grandmother. The logic behind this is that, if you go back with such intent, the past will already have reflected that. And, since your grandmother did live and your mother, and you, were born, you obviously already failed your mission. Something will stop you (or already has stopped you, as the case may be) from killing your grandmother. I think the most likely cause for this prevention would be your own untimely death. Thus, going back in time to kill your grandmother would simply be suicide. No major breakdown in the space-time continuem.
If you like books that address time travel, the I suggest you read "The Door into Summer" by Robert A. Heinlein.
Back on topic, there is nothing wrong with reloading to get a different result, so long as you are not submitting the game to some competition and telling other players that you have not reloaded. BigWiger now knows the value of an alliance, and might not encounter this problem again in the future.