He didn’t need to apologise as he was telling the truth — the money spent on employing workers is a part of the capital invested in a business. So referring to workers as “human capital” is accurate enough. The term Marx used was “variable capital”.
Of course the Winters character was never going to be that accurate as that would be to
let the cat completely out of the bag. Marx called the part of capital invested in employing workers “variable capital” because, unlike the other parts of capital — plant, machinery, materials, power, which only passed their value on to the product unchanged — the part invested in employing workers increased its value, the surplus being the source of profit and other property incomes.