In simple terms, that assertion is correct, but for those with an expertise in the field, the longer answer to who did it ...

Robert Oppenheimer's name has become almost synonymous ... Harvard in 1925 and studying at Cambridge University under Ernest Rutherford. In 1929 he returned to the United States and positions ...

J. Robert Oppenheimer was an immensely complex figure, and the movie's based on a biography of him. While the movie is historically accurate in many ways, there are a few bits of fiction mixed in.