Your graph-augmented system states a fact with a clean...

The hallucination arises because the model generated reasoning based on retrieved context, but the system failed to validate the reasoning steps against the actual graph structure. To prevent this, you must implement a grounding step that forces proposed relation paths through a constrained BFS from the question entity. Any path that does not match a real walk in the graph must be discarded. A weak answer suggests fine-tuning the model to hallucinate less, which ignores the necessity of graph-side verification.