Quan Yunsong now revered Ye Fan as a Divine Doctor, because he had no idea how Ye Fan had discerned that his gunshot wound had healed, leaving only a scar—and he was still in his clothes. Unless someone knew the details, it would have been impossible to be so informed.
Quan Yunsong was certain; he had never met Ye Fan before, and only very few core members knew about his gunshot wound.
Therefore, Quan Yunsong believed that Ye Fan was a Divine Doctor, otherwise there was no other explanation.
Quan Yunsong had heard of Divine Doctors in the past—some could infer whether your parents were ill based on your condition, which has a scientific basis due to genetics shared between children and parents. Thus, it's feasible for an impressive Divine Doctor to obtain such information.
Quan Yunsong speculated that Ye Fan must be of this caliber, able to deduce illnesses based on facial complexion and other indicators.