Lenore's point is that thinking historical explanations can be objective is naive. In rebuttal, Victor provides evidence of those who identified biased thinking, concluding that Lenore is incorrect. However, the evidence that Victor provides us with can be completely consistent with Lenore's claim. Just because people can identify biases, doesn't mean that they, themselves, are not biased. Victor's response does not succeed as a rebuttal because he has given us insufficient evidence. This is the flaw of the argument: Insufficient Evidence.
Hope that helps! Let me know if you have any other questions.
