Cultivating the Tao and cultivating Buddhism are two different concepts. Just like the Mount Tai Sect, they have their own set of spells and cultivation techniques. After discussing those spells and techniques, there would be attempts to learn others. If they belong to different systems, would the two conflict?
For example, previous cultivation levels might be lost when learning a different system of spells.
This question puzzled not only the Taoist but also Huang Chen, who had secretly heard the conversation and, like his master, couldn't figure it out.
Whenever he thought about how it was his act of murder and plunder that led the man to a fortuitous encounter, to revive from death and become even more powerful, and then to seek revenge on them, Huang Chen regretted it so much that he felt green with envy.