Looks like at one point it _was_ `len(grades) == 1`, but @ichuang changed it in this commit https://github.com/edx/edx-platform/commit/4d5ca284b2c798c6d3c0d1e71d05ae649e5dbc29. 

@ichuang , @ormsbee , why was it changed? What does the current condition capture (since `grades[0][0]` is almost always `None`)?