Quote Originally Posted by ejburke View Post
Then Halo 3 has to come in and confuse everyone by demonstrating that Halo does indeed kill the Flood.

Now it's a convoluted mess, with retcon on top of retcon being used to explain things that didn't need to be explained if only they had their shit straight all along.
The firing replacement ring for Installation 04 wasn't what killed the Flood. It was the resulting explosion from the huge amount of energy that ripped it apart, completely destroying itself and as Cortana states, "did a number on the ark". In a way, it was the same way the Flood on the original Installation 04 perished, from the rings destruction.