From a historical point of view, when Lin Ran launched Flesh Sacrifice, he was already dead in any previous timeline.
In that case, the Tiger Soul Research Institute was fully infiltrated decades after his death.
However, on careful thought, this answer was obviously wrong.
When he first joined the Science and Technology Research Institute, he had tried to sow discord between it and the Tiger Soul Research Institute. Moreover, the Science and Technology Research Institute really used the Truth Artifact to catch the spy planted inside it.
In other words, when he was still alive in the previous timeline, the Tiger Soul Research Institute had already been infiltrated.
Therefore, the time span could be reduced again.
From the current intelligence, he felt that the Tiger Soul Research Institute was truly infiltrated about ten years later.
It was also the years when he was close to death in the previous timeline.
