They had a choice to make: country-wide lockdown and travel ban or lie about it and make it spread worldwide. The former would leave their economy in a disadvantaged state while the latter would level the playing field for the rest of the world and give China opportunity to even earn some dough in the process (PTE sales). Now, this may be a cynical view but so are China's leaders. If you're someone who strongly believes this scenario could not have transpired, you're just naive.