Coming from some experience in different styles of aikido, I've noticed a difference between the details of sumiotoshi and hijiate nage. I think the original idea of hijiate, in respect to aikido, was basically a joint strike. Maybe a DRAJJ person could answer up if they have hijiate in the hiden mokoroku or something like that? That being said...does anyone else call variations of this technique sumi otoshi? We had it in the AAA curriculum... the main differences being elbow placement and how the projection is being conducted.
Here is a really good (albeit in Japanese) demonstration of many Yoshinkan variations of hijiate nage by Inoue Kyoichi Sensei (hakama):
http://www.youtube.com/watch?v=qgBTi1lrg10
hijiate goes until about 2:15 mark then goes into some Yoshinkan Jiyuwaza.
As far as calling it sumiotoshi (soto sabaki) I can't find any clips of that...so we must be in the minority on that one...most people seem to do just the uchi variation....or even a kokyunage in the technique their sumiotoshi.