Only then did he realize that the king of spirit beasts looked like it was helping Lin Yi out, but it was actually helping him out as well. No matter how he looked at it, it was more likely that he had crossed paths with the new king of spirit beasts. Maybe he was really noticed.
Not to mention, Lin Yi's spirit beast aura was all a disguise during the spirit beast meet. Normal spirit beasts wouldn't be able to see through it, but it might be a different story if it was a King of spirit beasts. Even if it was just a puppet king that the Vermillion Bird found to trick people, it had to have some skill.
This new king of spirit beasts sensed the aura of the ghost and suspected that Lin Yi was one of them, or even the ghost itself. This was probably the most plausible explanation.