Father McBrien seemed to get into trouble with the Church with the publication of his book “Catholicsm”. He was unable to get Church approval to publish this document. The NCCB’s Committee on Doctine took issue with some of his more creative theological points. They asked him to make changes. He changed some things, not others. You can read about it
here He still had the book published.
When Ex Corde Ecclesiae came out, he was very vocal in his dissent to that document and refused to get a mandatum to continue teaching theology. As I understand it, he is one of the main reasons why ND is not in compliance with Ex Corde but I am sure he is not alone. If you do a google with his name and Ex Corde, you will get lots more info.
Since then, he has been somewhat of the darling of the TV talk shows where along with Father Andrew Greely, he speaks about how the current Church is “out of touch” and ready for change. (blah, blah, blah).