Few principles are more depressingly familiar to the veteran scientist: the more surprising a result seems to be, the less likely it is to be true. We cannot know whether, or why, this principle was overlooked in any specific study. However, more generally, in a world in which unexpected results can lead to high-impact publication, acclaim and headlines in The New York Times, it is easy to understand how there might be an overwhelming temptation to move from discovery to manuscript submission without performing the necessary data checks.
This is not just an issue in genomics. I've discussed it before as being a major problem in psychology. Though the infamous centenarian study will do nothing for the careers of the scientists involved, I do wonder what the effects of publishing large numbers of false positive results in science are on an individuals' career when it isn't so inexpertly executed (i.e., in this particular case the technical errors were so glaring that the authors should never have submitted their findings). I wonder because apparently major newspapers are now running with stories which they know are highly likely to be exaggerations or misrepresentation to induce pageviews, and then subsequently 'correcting' them. More specifically, the number of corrections has been rising rapidly.