And I agree with you; The statement made in the post before this one is rubish...
Its all rubish... The whole idea of a planet exploding is just plainly foolish.

Lets look at what could cause a Planet to explode.

1. Collision, yes that could do it. The odds are stacked in our favor. This is not a high risk area., and our technology is getting to a point where we really can save the Earth from a major collision event.

2. One of the life forms that dwell on this planet might poison or otherwise destroy this environment. We could do one experiment to many and covert the whole thing to anti mater in a flash of mindless cleverness.

and there's bound to be a much bigger list... That I will continue to ignore.