It’s not a theory. It’s a possibility. Not a likelihood or a probability. The probability is that it was deliberately released. If you were China, and you wanted to introduce a virulent pathogen into the world, how would you do it that would have been substantially different from how it was actually done? I have heard the saying to never attribute to malice what can be easily explained by ignorance, but that lets a lot of malicious people off the hook if they can say they didn’t know or didn’t mean. It’s a stupid rule. There are lots of malicious people in the world and many of them are in positions of power.
I wouldn't release it in China.
Best bet might be to release it in several of Europe's busiest airports.