Except that her statement was a blanket denial of any wrongdoing, including any illegality, failure to follow IRS procedures, and providing false information to Congress. Essentially, everything in the scope of what she's being asked to testify about. She opened the door, and she is no longer able to shut it.
Her statement has nothing to do with the greater question.
Each question stands alone, and nothing in your desire to prosecute her can change that.
If she has perjured herself, we will have the chance to see Issa fold without cause.