Clodovis Boff rather famously broke with his brother Leonardo some years ago Eponymous Flower has a short piece on Liberation Theology and carries this quote from him:
"In the two documents published by Cardinal Ratzinger, he defended the original core of liberation theology: the commitment to the poor because of the faith. At the same time he criticized the Marxist influence. The Church can't do this. It's not like a civil society where people can say what they want. We are tied to a belief and if someone professes another faith, he closes himself from the Church. From the outset, it was clear the importance was to make Christ the foundation of all theology. In the hegemonic discourse of liberation theology, however, I have noticed that faith in Christ only appeared in the background. The anonymous Christianity of Karl Rahner was a great excuse to neglect Christ, prayer, the sacraments and the mission in which the focus was only on the change of social structures. "