The GOP is not interested in truly investigating the IRS scandal. Behind closed doors Boehner and McConnell are likely cheering on the IRS in their efforts to kill the tea party. The GOPe leadership is letting the IRS take the lead in killing the tea party so they don't have to work as hard in killing it themselves.
Yup, backroom everyone is highfiving each other and congratulating themselves as they play good cop/bad cop again.