Answer:
Bob Wilson was startled when Oppenheimer called the Japanese <em>"those poor little people" </em>because he understood the painful sense of both sides.
Explanation:
In an interview with Frank Stasio, Mr. Bird reveals the incident when Oppenheimer talks about Japanese and calls them "those poor little people." Bob Wilson was startled by this statement of Oppenheimer because he was able to understand the painful sense of both sides. It was the time when Oppenheimer was instructing people where to bomb.
Textual evidence:
<em>"And she asks, `Who are you talking about?' and he says, `The people who the bomb is going to be used on, the people in Japan.' And this is the very week where he's also instructing the bombardiers exactly how to drop the bomb, at what height to achieve the most maximum destruction. So he understood, you know, in a painful sense, both sides, the necessity as he saw it at the time, and yet, the horrible human consequences of it."</em>