I am in awe of his reaction. Pretty sure I would be standing there thinking “what just happened?”.
I responded just as fast to a similar situation once, but without any of the risk and heroism. I was standing next to a fully dressed little girl at the edge of a swimming pool, when she spied a cute white pet rabbit directly across the pool. She tried to walk across the water to pet him. I had her out in about five seconds, drenched and crying. Didn't even have to jump into the pool.
I hadn't thought of that in many years, but this video really brought back the memory.