Some anti-oppressive thinkers distrust powerful institutions, and end up distrusting the scientific institution and even scientific knowledge itself. However, scientific knowledge and scientific practise are not inherently oppressive. The oppressions that appear to come from science actually come from the upper-class white male domination of scientific disciplines.
Science is not the enemy; the practise of science is a productive method for understanding ourselves and our world. When some scientific studies overgeneralize and/or neglect certain groups of people, the problem is bad science, not science.
One of the serious problems with the lack of diversity in the practise within certain knowledge domains is that some important aspects of reality are not even considered, leading the researchers to overgeneralize and draw incorrect conclusions. This problem comes from the fact that scientific practise is a social activity, subject to the biases and prejudices of the scientists. In contrast, the scientific methods of gathering empirical data to refute hypotheses, and using statistical methods to determine statistical significance, are perfectly sound.
It is illogical to assume without reason that the results of a given scientific study (especially one that you do not particularly like) must be false. There is no contradiction between truth and justice. Anti-oppressive thinkers should not be afraid of science.