Chapter 37 EOC Question 5 (Pg 168 of Book 5) understand, positive, decrease, increase, interest

transferpricing

In the solution to question 5, it says that when interest rates increase, the NPV of cash flows is negative and the investor never recovers from the increased interest rate he faces on the overpayment of the 1st swap payment. When interest rates decrease, the NPV is positive because the investor gets a favourable interest rate on the loan he needs to take to finance the first overpayment. What I do not understand here is why does the investor need to take a loan to finance the first overpayment in either scenario? Any ideas?