Include the position of the elbow and footwork please. What are you thoughts? The horse must be well grounded whether or not you are turning it or stepping in, or else you will be off-balance during and after the strike. This is where video really helps. He left with bruised arms and ego. I personally havent been able to achieve anything like that cuz I stopped my Qigong exercises temporarily accept 8 brocades until I learn all the Taiji forms my teacher is teaching I was at the right angle watching and saw the incoming punch get it's energy dissipated downward by Sifu's tan and structure with very little effort.
Now perform the same drill while walking forwards:
Pigua Tongbei: Swing Your Arms Like a Great White Ape
This is but one technique of wing chuns aresenal. As you turn, raise your left arm straight forward to shoulder height. I popped this question to my sifu at my club and some of the seniors. Each art has examples which can make its core principles work and work well. I have superb contact at this point.