Israelian and coworkers showed that the stellar companion of the black hole binary Nova Sco is polluted with material ejected in the supernova that accompanied the formation of the black hole primary. Here we systematically investigate the implications of these observations for the black hole formation process. Using a variety of supernova models, including standard as well as hypernova models (for different helium star masses, explosion energies, and explosion geometries) and a simple model ...