Earlier, the third child had told Zhao Luofei that Fang Zhou's name was related to a floating boat.
Zhao Luofei had speculated names like Fang Ping, Fang Fa, Fang Ya, Fang E, and eventually chose the most likely one: Fang Chuan, because she thought it sounded quite nice.
It's just a lack of cultural knowledge; after all, Zhao Luofei came from a military background, so her education was limited to basic literacy.
Fang Zhou didn't expect Zhao Luofei to come up with such an unlucky name for him.
Fang Chuan capsizing? Was this hinting that he would eventually 'capsize' one day?
Just kidding, I'm a rowing expert; capsizing? That's impossible.
Zhao Luofei saw Fang Zhou's expression and realized she had guessed wrong, and said somewhat embarrassedly, "Sorry, I was just guessing."
Fang Zhou shook his head and said, "Actually, you were pretty close; you just got one character wrong."
Zhao Luofei had a sudden flash of insight and said, "Could it be Fang Zhou?"