Edit: Because the former doesn't sound like much of a conspiracy, aside from a cover-up afterwards.
From there, the only safe bet is to act as if it were intentional.
This is a controversial concept, but it is the rational choice. Never assume that someone who harms you is doing it accidentally. Even though it is more often than not the case, you still have to protect yourself with the possibility of malice in mind.
For one, if we assume it was released from a lab and that was intentional, the what was the intent?
If it was to do what happened — kill millions and devastate the global economy — then the right reaction is a very severe cold war or possibly outright war. We literally could not allow it to happen again.
But if it was released from a lab unintentionally, the right reaction is to spare no expense, regulation and treaty to secure such labs from this ever happening again. This would go for all labs like this, not just Chinese ones.
These are entirely different reactions with entirely different costs and long-term ramifications for peace and stability for our world.
Not to mention, the intentional release scenario doesn’t really make sense. E.g., China couldn’t damage our economy without damaging their own. And if you’re going to choose where to start the pandemic, why start it in your own country near a bio-research lab? If it was started intentionally, it makes more sense that China was framed. (Still doesn’t make a lot of sense though because what’s the rational motivation?)