http://www.thecrimson.com/article/2010/9/21/school-system-students-law/The changes, which will allow the Law School to calculate Latin Honors more precisely, were put in place over the summer and included in the 2010-2011 Handbook of Academic Policies, but were never publicly announced.
The biggest change is that each grade will now correspond to a point value—four points are awarded for a High Pass, three points for Pass, two points for Low Pass, and zero points for a failing grade.
Looks like, even without grades, there are still grades at HLS.