explosive testimony delivered in Seoul

Why would a Chinese engineer go to South Korea to testify this?
It was a Samsung engineer that allegedly copied the information.

Samsung spent over five years and roughly $1 billion to develop and refine this specific 18nm manufacturing node.

CXMT was founded in 2016 according to the article, in 2016, even AMD had 14 nm process production for their Ryzen CPU.
And if I remember correctly Intel had 14 nm for 4 years at that time, and Samsung and TSMC introduced 10 nm in 2016 so this was the year TSMC arguably surpassed Intel for the first time.

So stealing 18nm technology AFTER 2016, is stealing already pretty old technology. And I bet SMIC ( The leading Chinese manufacturer ) would have been pretty close to 18 nm that at the time, as they introduced 14nm in 2019.

So this does not pass the smell test IMO.

Also Samsung stole technology from TSMC, and TSMC got theirs early on from Intel.
TSMC however did this AFAIK in a legal agreement with Intel. And the founder of Intel of course invented the semi conductor, so they are probably in the clear.

if ITC rules that CXMT relied on misappropriated trade secrets. ITC could issue a blanket ban blocking those products from entering the U.S market.

Just as I suspected even before having read the article.
First they deny China access to the best chips to prevent them from being competitive, and now they want to prevent China from exporting their chips.
The 22nm process they began to use in 2019 seems like the same 22nm process SMIC used until 2019 where they introduced a new 14nm process. It seems much more likely that CXMT got their process tech from SMIC.

I kind of hope USA will ban the Chinese chips so we can get more here in Europe. China will manage anyway, and USA will become less competitive.