I just happened to be scanning the 2014 Chicago Marathon leaderboard splits (I know, get a life right?) and I noticed something bizarre. Abdellah Falil of Morocco has a 25K split of 1:16:13. Up to that point, it looks like he was running splits roughly between 15:05-15:15 with Koji Kobayashi of Japan. Then he manages to hit 30K in 1:29:43, meaning he split 13:30 between 25K and 30K. He has no more splits after that, so he appears to have dropped out at some point after 30K.
Is this an error? Did he cut the course or something? If not, is this the fastest 5K split ever recorded in a marathon? I don't think I've ever heard of anyone splitting faster than 14 flat.