Say a group of animals intended to be euthanized were actually clandestinely sold at the market, it's completely reasonable that the virus could have mutated at the lab in the animal population before being transmitted to humans. In fact, this is literally exactly what occurs during gain of function research, when scientists are explicitly trying to get a virus to mutate in live animals.
There is simply not any hard evidence to concretely prove either hypothesis. Any evidence that points to the market can just as easily be involved in a lab leak scenario.
When you have no comprehensive data on transmission, and no audit trail of how the animals arrived at the market, it's not possible to determine origin from super spreader. The evidence for both would look identical!