There were several things wrong with what Hou Ruyen had said and Sikong Ren was quietly processing them while maintaining a calm and straight visage.
First of all, she confirmed that she was really there to check on the state of Zhang Sun's corpse, rather than visit him like usual. Why was she checking in the first place? Sikong Ren and Zhang Wang had only done so because of the strange hints that lay about and Hou Ruyen claimed not to believe in the tales of a ghost.
The other thing was the fact that she had checked, either confirming that the corpse was still there or that the coffin was empty. Either way it would have painted her in a light of suspicion; if she claimed that the coffin was empty then why didn't she mention that something had been awry? And if she claimed otherwise then why did Sikong Ren find nothing below the soil with his spell?
Quickly tossing this out before I yeet so my boss doesn't catch me doing non-work-related things welppp