From the article, "The Independent Tribunal into Forced Organ Harvesting from Prisoners of Conscience in China heard evidence in public in London on 8-10 December. A seven strong panel questioned 30 witnesses, including refugees from China, doctors, and investigators.". Clearly, solid and irrefutable conclusions on such a serious matter only need 3 days of hearing from 30 witnesses.
I found the title to be misleading. How clean electric cars are, as the article discusses, is determined by the sources and processes used to generate electricity. It's a national energy infrastructure problem, much bigger than electric cars alone.