The premise of the author's argument seems to be "don't worry, the programmer won't do anything bad with the code". I don't think it's such a good idea to just implicitly trust that an employee who downloads your source code isn't going to do something unethical with it.

(especially in an environment in which the owner of that code, i.e. Goldman, has already taken great pains to prevent copying of the source code, such as removing physical access to the PCs, etc)

Goldman has to protect their shareholders in this kind of thing, and there really isn't any room for "let's just trust this guy won't do anything harmful to us" in that.