In October 2015, Firm G completed a consulting engagement and received a $200,000 cash payment for its services. In December, the client notified Firm G that it was unsatisfied with the work and demanded that Firm G refund $50,000 of the payment. Firm G refused and referred the matter to its attorney. In 2017, Firm G settled the dispute by paying the client $30,000. Firm G's 2015 marginal tax rate was 39 percent, and its 2017 marginal tax rate was 34 percent.

Identify the tax issue or Issues suggested by the following situations, and state each issue in the form of a question.