What Ban is referring to is the fact that the UN Human Rights Council chooses its targets with, shall we say, a prejudiced eye. For example, it has issued repeated condemnations of Israel while showing a strong reluctance to denounce rights abuses elsewhere, including consistently blocking criticism of the Sudanese government for human rights violations in Darfur and protecting Zimbabwe’s Robert Mugabe from censure.
Of course, this happens because the UN doesn't really take into account the quality of human rights when appointing members of the Council. Currently, African and Muslim countries have a majority of seats on the 47-nation body. This results in a regular flow of anti-Israel rhetoric and an ethos of African solidarity. Both effects prevent the body from being sufficiently objective to do its job.
This problem is indicative of the central problem of the UN: that it regards all sovereign nations as equals (apart from the Security Council nations). Maybe if the UN were a little more selective in terms of which countries were allowed to be on the Human Rights Council, its statements and condemnation would be a little more reflective of reality.