LONDON — Michael Phelps flipped away his cap in disgust, having blown the race with a blunder at the end. He hardly looked like the swimmer who had just equaled the record for most Olympic medals. Phelps won his 18th career medal Tuesday night, but it was only a silver. Having led the entire way in the 200-meter butterfly, he tried to glide to the wall after his final stroke and was out-touched...