A humanoid robot beat the human half-marathon record at a Beijing race. But what did it actually prove?

Last Sunday, at the Beijing E-Town Half Marathon, a red humanoid robot of a type named Lightning finished the course in 50 minutes and 26 seconds—faster than the human world record. Its long legs were modeled on elite runners, and its motors were cooled with a liquid-circulation system adapted from the smartphones of its maker, Honor, a Chinese phone company. A clip of the robot’s performance that ricocheted around the Internet looked to a lot of viewers like a milestone. It was, and it wasn’t. The Lightning robot also crashed into a barricade, fell and waited for its handlers to…