Near the beginning, you can see the wooden board that the cameraman walks on in the bottom right corner.
In the opening hunting scene, the forest is completely wrong. There are no temperate rain forests in Florida, much less in the Panhandle.
The Latin phrase "Ad Noctum" on the post is bad grammar, should be "Ad Noctem."
Scully says, "If I can separate the shell from the casing, maybe I can get the powder to ignite." A shell is a casing. She should have said, "If I can separate the shell from the bullet/slug, maybe I can get the powder to ignite."
The father and son should have been wearing hunter orange clothing or at least a vest as they might have been mistaken for animals and shot themselves. If the father was experienced hunter he would have known that.
After Scully fires multiple rounds from her weapon, Mulder asks her if she has another clip as backup. Any entry level firearms enthusiast or greater knows it's a magazine and not a clip. Being FBI agents with fairly extensive training, as well being the wordsmiths that they are, Mulder and Scully would never have called it a clip.
Mulder pronounces the word "conquistadors" as "con-kwistadors".