They did fudge their numbers, for a while their case numbers were growing exponentially, but almost perfectly so, with zero random noise, so you know they were fudged. At one point, people were starting to predict their future numbers correctly down to the single digit. I think they probably underreported their Wuhan casualties early on and at the peak.
This being said, there is a range beyond which it is hard for them to lie, China is still a somewhat open modern society with widespread use of VPNs, it is not North Korea, there are a lot of first hand reports and expats in their main cities that could verify or deny official reports. There is no doubt that their epidemic is well into the decline phase, cities like Shanghai or Shenzhen have been at a more relaxed regimen for a while now.
