I have a couple of issues with this clip.Does this clip show the CMA principle, "手不空回 One should not pull his punching hand back empty"?
The first, as Gerry notes, is distance. Your initial swing misses your partner by over a foot without him doing anything to defend. Likewise his counter-swing would miss you if you weren't coming to meet it. At the moment he starts his swing you are well out of range.
The second is speed and timing. You partner starts his swing just a moment after you start yours and you can see at the moment your hand is at the top of your first swing his fist is at the bottom of his swing. Then in the time it takes him to complete his rotation to the top of his swing your fist has finished its downward swing, changed direction in a figure-eight loop and come all the way back up and out. In other words, your fist has travelled twice as far as his has in the same time. I don't like any technique which depends on the idea that you can move twice as fast as your opponent.
The thing is, something like this technique could potentially work with realistic distancing and timing. Perhaps you throw a hook at his head, he bobs and weaves underneath, you continue the arc of your strike back around into a backhand, but he's coming back with a slightly late counter-hook of his own, and due to some accident of timing and footwork your back hand strike intercepts his arm rather than his head, so you turn that into an arm wrap. However the change in distancing and timing will make it feel significantly different from the way you are practicing it. Also once you apply realistic distancing and timing then it becomes an occasional opportunistic technique that you go with when it falls into your lap, not something you can drill for consistent application against a competent fighter.