It’s possible there was a lab leak, and relevant labs should be investigated for the same reason we investigate all plane crashes, it either leads to finding gaps in processes or confirms whether or not a systemic issue was a factor. The probability has decreased as COVID has been further researched and shows more markers of a ‘natural’ development, but it’s generally beneficial to have a comprehensive audit when processes are in question.

That’s not what these people are arguing. They’re arguing that it’s China’s fault and not Trump’s. That’s it. For that to be the case it ‘must’ be a lab leak, and so they’re retroactively finding justification for how that is possible. That they’re running parallel to a reasonable line of logic for a portion of their argument does not validate their argument.