I don't think that the author of the parent comment has some "i don't believe the system" sentiment, tinfoil hat style.

For example, I definitely trust CDC (the US one). However, I am vary of trusting Chinese authorities and agencies when it comes to this issue, as they have shown before that they are willing to go to extreme lengths to hide the truth when revealing it casts a bad light or reveals some info. I have no strong opinion on the true source of the virus, as there isn't simply enough info and time to do a proper investigation by CDC, but it is easily imaginable how much the reputation of China will get damaged if it gets discovered that the virus was born out of one of their labs.