scientists led by archaeologist Prof Mark Collard of Simon Fraser University in Vancouver say the truth may be far more gruesome. “There is compelling evidence that these people may have had their fingers amputated deliberately in rituals intended to elicit help from supernatural entities,” said Collard.
Except that they (researchers) are claiming to have an idea of why something (fingers) is a certain way (chopped-off in cave paintings).
If you review their research and find cite-able problems with it, fine, but they’re specifically asserting that they have reason to believe that these amputations were real and inspired by beliefs in supernatural deities.