Nonetheless, this piece isn't "thoroughly checked" because there is nothing to check. They took the deficient data from China and added suppositions to it. It's neat, I guess, but meaningless.
This paper is not being taken as authoritative anywhere. No one is making policy decisions on it. Zero ground-truth is changing because of it. Because it's a cursory, superficial guesstimate (that is literally the most accurate word) just to appease curiosity.