The lecture directly contradicted the passage in three aspects. First, a company would not increase its profits. The passage assumes that a company could save money by paying less for its employees and thus increase its profits. In fact, as the professor points out, the company is likely to spend a lot more! On the one hand, this company has to invest a large amount of money in providing training to new employees, and in the new one's medical ensurement. On the other hand, the fact of more employees means more offices and more computers, which would cost the company a lot too!
Second, the economic situation of the country as a whole, would not benefit, too. Because of the disadvantages of hiring more employees mentioned above, a company would not be willing to hire new people, so the unemployment rate would not decrease.
Third, this policy would not be good for the well-being of employees. A company might ask its employees to do the same amount of work in four days as they used to do in five days, since hiring new ones is costly. It seems at first glance to be true that employees would have more free time to do personal things. However, this would also bring employees risks. An employee who works four days a week is more likely to lose his/her job in an economic depression than a five-day-work one.