A market spillover requires (i) a susceptible host species physically present and (ii) conditions of intense, bloody, high-density human-animal contact. Raccoon dogs and civets are experimentally SARS-CoV-2-susceptible and were the intermediate hosts in the 2003 SARS-CoV-1 civet-market spillover; here they were sold live in volume, caged and stacked, with on-site slaughter that generates aerosols and fluid exposure. Both conditions are therefore met, making a SARS-CoV-1-analogous market spillover mechanistically viable and raising its prior. Limit (for scoring): feasibility is not occurrence - the survey shows the opportunity existed but provides no infected animal, so it cannot by itself establish that a spillover happened.
Verdict (step 6) — approved, checked
Reconstruction. Premises: (i) raccoon dog/civet/mink are experimentally SARS-CoV-2-susceptible and were the 2003 SARS-CoV-1 intermediate hosts; (ii) they were sold live, in volume, caged and stacked, with common on-site slaughter. Load-bearing step: satisfying both animal-side preconditions of a market spillover (susceptible host present + intense high-contact/aerosol-generating conditions) raises the prior of the market-spillover route relative to a world lacking either.
Evaluation, conditional on premises. This is a bounded evidential claim (“raising the plausibility / its prior”), and the argument itself flags feasibility ≠ occurrence. An undercutting defeater would have to show that establishing the mechanistic precondition does not raise the route’s plausibility — impossible unless the route were already certain or already impossible, neither of which holds. The step does not smuggle in occurrence (no infected animal is claimed), so it does not overreach. Approved. Traced directly — checked.