Ah, once again xkcd gets it right. Non-scientists would be forgiven if they believed science advances through press releases and not through actual research, vetted in various ways by fellow researchers.
Some of the problem lies in the way science often is funded and managed: the researchers are beholden to various funding agencies and are under pressure to get definitive results. So preliminary results that may or may not be substantiated later on are picked up as the greatest discovery ever. This xkcd comic goes even further, having the reporters pick up on a public misstatement, but the joke would work just as well for more common scenarios—where scientists say something is tentative, yet it is still reported as the greatest discovery ever.
(For the record, as funny as this comic is, I don’t play Minecraft.)