Goofs

During the chase of the second girl, the really fast sunrise transitions so quickly it almost seems like the night suddenly changes into day.

When the girl goes up the ledge, a shot of it from the sky is seen. Near the end of the movie a similar shot is seen, but its a completely different ledge that doesn't even look close.

In the final battle scene between Kelly and Josh, blood can be seen coming out of Kelly's nose before Josh first punches her. In subsequent shots, Kelly only has blood coming out of her nose from the wide shot, whilst in the close-ups her face is blood-free.

When Kelly kicks Taylor off the cliff he lands flat on his back but manages to break his leg. Furthermore, his leg can be seen shattered before he even hits the ground.

When Sophie is first injured, Reynolds tries to call the emergency services on 911. That wouldn't get him far in Italy, where the emergency services number is 112. However, this is a mistake by the character, which is in keeping with the character's likely behavior, so is not a goof.

During the chase, it appears that the girl hides the camera in the woods under some grass when in fact she dropped it and is scrambling to find it in the dark. She grabs it and runs away. Shortly after that, she drops the camera on a ledge, then it appears that she climbs down to get it even though they don't really show her climbing downward. However, not showing something happening in detail, is not a goof.

The snake on the mountain is a boa constrictor. A tropical snake that are from South America, and wouldn't be able to survive in a mountainous region of Europe.