I hadn't thrown with Tomoe Nage like that since I was a sophmore in College and realtively new to Judo (I was a yellow belt - Rokkyu). My partner at the time was a freshman white belt, and my Sensei was pissed that I used a throw he had never seen before - rightfully so, I could have hurt him. But this time it was against another sankyu, and he admired the throw too.
What is this variation that I used? I call it Goofy-foot (in deference to the snowboarding term for leading with your left foot). Essentially, traditional Tomoe Nage has the tori taking the foot on the lapel side and sticking it in the uke's gut to launch him over your head. In this variation, you use the foot on the sleeve side so that uke doesn't see it coming.