User blog comment:Kogath/Monster Hunter X Discussion/@comment-20010297-20150909201359/@comment-25275196-20150911123350

Lao shan might go after the hunter in other curcumstances, but he's a lot more afraid of Fatalis than any midget human, he's just trying to get out of there as quick as possible, and the fort is in its way, so it destroys it. An aggressive Lao would need to be fought in its natural habitat, and not the fortress. It's like how the shen fight was so different depending on if you were in the town or the fortress.

If Lao shan went aggressive while in the fortress, it would be a sure sign that Fatalis isn't in the game.