List of MC's logical fallacies in this chapter:
1. Assumes that slaves must be from another world, as if slavery is not a thing in the real world (it's generally no longer governmment sanctioned, but slave trafficking is totally a real thing).
2. Assumes that someone who can get into his locked house must be from another world.
3. Assumes someone who speaks a language he's unfamiliar with must be from another world.
4. Sees magic performed in front of him and calls it unscientific. Anything that is observable per definition cannot be unscientific. Being unscientific would be drawing conclusions that contradict the scientific method (for example. if two different claims both fit a set of evidence, you believe in the more complex claim rather than the simpler one). If anything, him repeatedly jumping to the conclusion that everything is evidence of the girl coming from another world is what's unscientific here.