Very good discussion in a sibling comment. From my side, surely the lab leak prior probability is not 0. It is possible so must have a positive probability. No

Very good discussion in a sibling comment. From my side, surely the lab leak prior probability is not 0. It is possible so must have a positive probability. Not is it, a priori, a crackpot theory. The crackpot bit is when people are totally convinced of it with no or shaky evidence.