In 2014 BICEP2 made a very controversial press release. It was rushed, given before any papers where published, because they feared they would be scooped by another similar experiment. In the end it turned out that their analysis of their data was flawed. It was particularly dramatic because if they had been correct it would have been a significant development.
Are there any similar cases in biology? Not necessary an identical situation, but a high profile result that was released in a hurry that later turned out to be incorrect.