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.
It was the straight-line description that reminded me of the Shodokan "shihonage," which I remember as moving aite more or less straight back and down (tori moving slightly to the outside of the wrist being "returned?"). Do you know of a good video that shows it? I googled/youtubed "Tomiki Ryu tenkai kotegaeshi" and "Shodokan tenkai kotegaeshi" but that blurry thing was the only one that popped up that had a similar look to what I remember; evereything else was tenkai kote hineri. It doesn't seem to be a very popular technique based on what kept popping up on my google searches, although I thought I saw a couple a few years back when I made similar searches.
At any rate, I remember really liking mae-otoshi and ushiro-ate a lot, I wonder why they stand out so much!