When they investigate the museum toilet, Mulder opens all stalls on the far side of the room, then he walks to the near side to open one of the stalls there. Then it cuts to a view from inside that stall and all the doors on the far side are closed again.
Mulder then opens three of the doors again, and when it cuts to a close-up of the three talking, the doors are closed again.
In the teaser, when the jaguar attack on Dr. Roosevelt is shown in silhouette through the tent from outside, it's very clearly a dummy in a chair that the animal knocks over.
The ritual of the Indians was with music from the North American natives, not the usual kind of music played by the natives in South America (Ecuador) with this kind of rituals, drinking Ayahuasca (Yagé).
The indigenous group shown is identified as the Secoya, who are wearing knitted chullos typical of the cold highlands. However, the Secoya inhabit the tropical Amazon region of Ecuador.