I know this is on the nikyu test so I paid attention when Dzung Nguyen Sensei showed this to the class I dropped in on. I was always curious how this would be done.

As the shomenuchi is on its way to my head, I extend my front arm and blend-meet his attack while my back leg slides so I am 45-degrees rotated from where I started. Then my other hand comes over his strike hand and I rotate my hips while grasping his tegatana; this then looks like a shihonage start from katatedori. I keep his arm extended and proceed as normal from this point.