I don't think the glide slope itself was the issue....but what appears to have happened is the pilot instinctively tried to keep the plane on the glide scope by increasing the angle of attack to the point the he could no longer see the runway out of the window. What didn't happen early enough was to realize why this was happening...i.e. why is the nose so high?
Because he assumed the speed was controlled by the aircraft, it was dismissed as a possible cause.