And let's not even begin to think what will happen if there were to be evidence that this was an intentional release.
If Covid turns out to be a lab escape (which is a big if), the nation or lab it happened in is just the proximate cause. Deeper responsibility would lie with the institutions and individuals that pushed it despite the risks. No one knows the answer to this (edit: I mean to whether covid escaped from a lab), but it's an open question that deserves credible investigation. Having the investigator be one of the principal funders of the research being investigated is such...bad optics, to put it nicely, that one wonders how anyone thought that would be ok.
[1] https://mbio.asm.org/content/3/5/e00360-12
[2] https://www.nytimes.com/2012/01/08/opinion/sunday/an-enginee...
That's the rational response. The fact that it can be played for political gain means it will be played for political gain, regardless of how rational it is.
Look at the whole mask debacle of the last year. If we assume people can and do act rationally, then both sides wouldn't have played it up as much and made it a defining issue or lied about portions of it, but instead we had both people and organizations/parties using it to rally their base (on both sides) and an authority that decided to use half-truths to trick people into doing what they thought they should do given the resources available at the time (to put it kindly).
That's the reality of the world we lived in for the last 12 months, and I see no reason to assume it's all of a sudden different. I'm not sure that means we shouldn't know, but let's be real clear on what the the likely outcome is if it's found to have escaped from some lab in China, regardless of who funded what or who was working on it, and that's that it would be a complete and utter shit show for the West and China, and possibly the entire world.