On June 3, 2019, Vicky Javier received from the Prudential Bank and Trust Company in General Santos City the amount of $100,000 remitted by her sister, Dolores through some banks in the United States, among which is Mellon Bank, N.A. On June 29, 2019, Mellon Bank filed a complaint against Javier claiming that its remittance of $100,000 was a clerical error and should have been $1,000 only, and praying that the excess amount of $99,000 be returned on the ground that Javier are trustees of an implied trust for the benefit of Mellon Bank with the clear, immediate, and continuing duty to return the said amount from the moment it was received. The Commissioner of Internal Revenue assessed Javier for income taxes based on the erroneous remittance received. Javier contended that the erroneous remittance is not gross income within the meaning of the Tax Code and therefore not subject to income tax. Question: If the bank failed to recover from Javier the amount of $99,000, is the money considered as an income subject to income tax? Why?