If I attempt the extrude region at 4:34 I just get the option to extrude the whole area in the z direction and nothing else. At 4:50 if I attempt a scale (via S key or scale button) I get an hour glass sort of shape rather than a clean 90 deg angle when the middle section is scaled down in the video. I can however achieve the latter effect via the 'extrude region (Vertex Normals)'. Is this all just due to me being on version 2.78 and the video being out of date?