Better safe than sorry.
Ling Han was confident, but definitely not conceited. If he still had overwhelming confidence in such a dangerous place, that would only be courting death.
He entered into the cave, and searched for the Celestial medicine.
—The Celestial medicine's medicinal fragrance, he could smell it from miles away, so with the sharp nose of a fierce beast, how could a fierce beast not smell it?
Thus, Ling Han would rather believe that there was something fishy going on than believe that this was really a coincidence. It just so happened that when he passed by, the Celestial medicine had ripened.
He walked slowly, and not long after, he arrived at the depths of the cave. Though this was not the end, it was pitch-black, and the medicinal fragrance was incredibly strong.