Is that a little like Shodokan tenkai kotegaeshi? This video is poor quality, but it's the best one I could find on it.
It's the second waza performed.
In Shodokan terminology Shihonage is tenkai kotegaeshi. I am a great fan of the first part of this technique since half way through is a transition point to mai-otoshi. For that to work best you need to be in control of uke's elbow using your arm in addition to control of the wrist. Usually the point of contact is just above tori's own elbow but perhaps (Phil will need to confirm) that all that shifts for his straight-line shihonage is the point of contact to the shoulder.
I find shihonage a very difficult technique to actually apply. When I have seen it successfully applied against a resisting opponent (and by that I mean a randori setting not someone standing there shutting the technique down) tori had to get low without that extra elbow control - it was also done very fast. My excuse is that I am pretty tall but that is my advantage during the transition to mai-otoshi which I have done to great effect. From the same transition point uke is nicely kuzushied to move into either ushiro-ate or pointing to another thread - a choke. Needless to say mae-otoshi and ushiro-ate are my favorite techniques.