Its a pretty safe bet that China doesn't report accurate numbers. But while they can lie about the scale and report 3,000 deaths instead of 10,000 - its not possible for them to lie about the end of the crisis. If people were still actually contjnuing to get sick in China now there is no way that they could be reporting the new case count at nearly 0 as they are now doing.
So even though we don't have a good sense of how many people were infected/died, we do have a very clear and reliable timeline for start to spread to end.