the revelation by kamov might contain some truth,despiter some doubt ,remember during 90's Chinese airframe design are very weak.china aerospace do not possess highly sophisticate testing facilites ,if you look at back issue of ConMilit Magazine ,in mid-90's a lot of Chinese make radar and missile fire control system still rely on analog system, alot of dial ,transistor and even vaccum tube, and small number of sc lsi IC technology. you just look at F-8-2 cokcpit, it was only in early 2000 's that PLA manage make the transisition from analog to digital.
Kamov didn't do the detail design of WZ 10 Here is my take on this subject. Based on my experience with preliminary engineering of industrial plant .Preliminary engineer can be divided into 2 category. So called concept study and Front end engineering.
Both start with simulation of the system. Basically throwing a concept system and see how they will performed( operational enveloped, range, MTOW, agility in the case of helicopter). Then derive the operational and extreme design parameter of the system.
Now front end engineering is more involved. They normally added a fair amount of proprietary engineering of their own. In the case of Helicopter maybe rotor system, avionic or gearing system.
They will do almost a complete and detail engineering of those system. They will get the other less component from other supplier but they will normally recommend their client to use similar component as in their product or design
For the privilege of using their system you have to pay royalty.
Now what I guess is China do the former. Why? Because you cannot buy or lease a helicopter code Not that many firm design and built helicopter. China is subject to dual use technology embargo.
The code like any other code is not just based on theory of rotor dynamic but it also incorporate accumulated experience that Kamov has with building helicopter. Now how can China has that experience when she never built helicopter from the clean sheet.
The fact that China never pay royalty to Kamov and use completely domestic components show that China do the detail design of the helicopter on their own ,build it, tested it. improve on that early concept design by Kamov.
Preliminary engineering is just like road map to get from point A to B. but like your GPS it might not the route that someone take because there are too many diversion like Traffic accident that might necessitate detour along the way.
By now China should have built the code by themselves and with booming both domestic software and hardware industry plus one design under the belt ,she should have master the helicopter design
The Design in completely own by China as Wu Ximing said in this video