Originally Posted by SleepNMnky
I'd almost bet that pop was one of the springs either breaking or coming unhooked. It's probably only one of several springs so you may not notice a change in the feel but if another spring comes undone you probably will be able to tell. Your squeak may be gone, but it's no "fix".
Or, more likely, the squeaky spring shifted into a new position, so now it doesn't squeak anymore. I doubt that a spring would "break". And it might shift back into the squeaky position again in the future. Who knows.