Can you tell me about the incident with the serpent in the barn and why the devotee was disappointed?

Chapter 35 details a fascinating event where a fearsome serpent entered a barn, causing widespread panic. In this moment of fear, a devotee named Nevasakar fearlessly brought a vessel of milk and placed it before the serpent. After the serpent was satisfied, it disappeared without a trace. As described in Chapter 35, Nevasakar's disappointment stemmed from the fact that he did not get to see the serpent leave. He felt that just as it was visible when it entered, it should have been visible while departing, but it eluded everyone's eyes.