Oftentimes the best we can do is make "educated guesses". Most domain experts, myself included, think it less likely that SARS-CoV-2 originated in a lab. This is not a unanimous position, and most scientists probably don't have a "dogmatic" view of this. Rather, we seek first to find and understand the consensus position, and then to test it.

That you or anyone else might disagree, or might not be able to imagine what type of mental model would lead to such an "educated guess", neither reverses the burden of the proof, nor eliminates the presumption of good faith, nor Occam's razor.

Taking the position that it came from a lab requires more assumptions and more unsubstantiated beliefs than not taking this position. It's just like Russel's teapot.