(This is why nobody has really used bioweapons in warfare to date, with the exception of some questionable reports that the USSR had a really lethal weaponized smallpox strain on some of their ICBM warheads, as a balance-of-terror multiplier.)

While this doesn't prove that COVID19 isn't a bioweapon, it strongly suggests that it got loose long before whoever designed it anticipated. Unless, of course, it was developed by the world-leading Vietnamese biological warfare institute (hey, look at their fatality figures)! (That was sarcasm, by the way.)