This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
The only time that the compiler will insist you add a return statement is if control reaches the end of a non-void method. That never happens here: before the method gets to the end, you throw an exception, which leaves the method, so no return is needed since it would never happen, anyway.