A wealth manager manages a $$100$ million portfolio for Mr$.$ BigShot, a ultra$-$high net worth individual. The portfolio has a well$-$defined benchmark in terms of asset allocation and choice of index for each asset class. The wealth manager asked an intern: "Please calculate the Active Risk of the Mr$.$ BigShot's current portfolio. I am concerned the portfolio is too different from the benchmark now". The intern first obtained weekly returns of the portfolio and of its benchmark over the last year. Then, using that data, he calculated the volatility of the portfolio returns, as well as the volatility of benchmark returns. Finally, he calculated the Active Risk of Mr$.$ Big Shot's portfolio as the difference between the two volatilities.

List at least two critical conceptual problem's with intern's calculations, and explain why these are problems and$/$or mistakes.