We buried it as a dupe of https://news.ycombinator.com/item?id=7647958, which covered Musk's news conference. The ULA suit wasn't mentioned in the title of that post but it was discussed quite a lot in the thread.

Points and time determine the position of a story. But if a moderator decides that he wants to, he can flag the story for a certain amount of position, 20, 40( next page )... You will probably only find such story only if you dig quickly enough using more.

It is an effective way of removing content. Deleting it would cause uproar, but that way the story fades almost unnoticed even to the commenters who noticed it.

There are also similar methods employed for specific users.