His response is based on the data. Looks like China, knowing they had a pandemic, didn’t stop travel. Hence, the were complicit in the spread either by ignorance or strategy.
That China would not stop travel of its infected citizens makes perfect sense from a ChiCom point of view: Minimize any bad press; share the virus with other countries so you are not the only country adversely affected; rely on other countries to get rolling with a vaccine or other treatment once they see it as a domestic problem.