During her lecture early in the movie, Dr. Collins shows a picture slide of what she calls a horned viper of the Cerastes genus. The snake in the picture is actually a copperhead of the Agkistrodon genus.
Near the beginning of the movie after Jonathan Scarfe's character arrives, the Sheriff shakes his hand sees his tattoo and asks if he was a Marine. Problem is the tattoo says USN - which stands for United States Navy.
The woman can't tell the difference between her lover's touch and that of a viper.
The snakes emit squeals when shot, burned or cut. This is unreal.
The snakes are shown biting off chunks of their victims. Snakes don't do that. They swallow their food whole.