LONDON — Early in the Olympic marathon on a rainy Sunday morning on the slick streets of central London, Kara Goucher found herself at the front of a brilliant field along with training partner Shalane Flanagan. It wasn't necessarily where she belonged or wanted to be. It just sort of happened. "We had no intention of leading," Goucher said, trying to find some humor in what was a grim day. "Both times I tried to go back to the second or third row, I got pushed and grunted at and stepped on, so I thought, 'What the heck, I'll just lead the Olympic marathon, why not? I have no shot at winning this, but I'll lead for as long as they'll let me.'"