I know its been a while since you asked this question but I’m leaving this answer as much for others as yourself. I am currently using Blender 2.77 and the only way I was able to get the single vertex to be placed was with CTRL+Left Mouse click. All other steps were the same; still in edit mode with nothing else selected. I’m not sure if this is because I have a setting in my build that differs from Kent and I am not sure what the setting would be. Hope this helps.
