For SARS-COV2 to have come from bats or pangolins it should have as much affinity for bats and pangolin as humans. Mutations are granular and only effect a few DNA pairs at a time. Not so with SARS-Cov2 which appeared with four entirely NEW amino acids that are PERFECTLY matched to a furin cleavage site found only in humans.
"This discovery came about when researchers at nference, an artificial intelligence company, started looking to see whether are there any sequences of amino acids in SARS-CoV-2 proteins that seemed surprising or unusual. One that stuck out, says Venky Soundararajan, nference’s chief scientific officer, was a stretch of four amino acids present in the spike protein of 10,956 of 10,967 SARS-CoV-2 isolates from around the world, BUT NOT IN THE PROTEIN'S SEQUENCE IN RELATED CORONAVIRUSES, SUCH AS SARS-COV OR VARIETIES THAT INFECT BATS OR PANGOLINS. Other groups had reported in February and April that this insertion forms a cleavage site for the human protease furin, which is thought to sever the two subunits of the spike protein to facilitate entry into human cells."
http://archive.is/dSAT6#selection-983.167-987.285
"Soundararajan and colleagues strengthened this idea when they determined that the furin cleavage site is identical to a proven furin cleavage sequence in the alpha subunit of the human epithelial sodium channel, which plays a role in managing the balance of salt and fluid in many of the body’s cells. This site is essential in the process of assembling the channel’s subunits into a functional whole capable of regulating sodium levels in a cell."http://archive.is/dSAT6#selection-995.0-995.447