Hand flying that approach would have undoubtedly revealed the GS failure much sooner, as you would expect to see deviation upon tuning to the ILS. If not then, you would expect to chase the beam at least a little bit.
There are a lot of presumptions made in autoland design, and one of them is that you won't have shoddy maintenance of the ILS. Autoland design basically assumes a Cat III quality ILS.
GB