This is an appliction of Kihon Kumite 1, where Nagashizuki is used to counterattack in the first movement.
Most of the time, pre-arranged methods called Yakosuku Kumite are unlike actual fighting. This does not mean however, that the principles and mechanics involved cannot be used for fighting. Without eleborating any further at this point, watch the video. You learn an example how to use Wado Taisabaki to absorb his attack and counter at the same time.