The pope understands what he's doing. Its more important to be spared of ridicule by the scientific community than to stick to the RCC's beliefs.
Every Christian should know the implications of "theistic evolution" -- namely that if God used evolution, there was no Adam and Eve. If there was no Adam and Eve, then "sin" simply never existed. If sin never existed, then Jesus either (1) never existed as a human anyway, or (2) he died for sin that never existed because Adam and Eve never existed, so his death means nothing.
No amount of mental gymnastics can over come the FACT that evolution completely contradicts the purpose and point on the Ransom, the central tenet of Christian beliefs. Therefore, the Ransom accomplishes nothing.