Goofs

At around 27 minutes, dirt on Sarah's face (her right side, mouth/cheek area) comes and goes between shots as she is sitting and talking to the rescue team underground.

Greg falls off of the cliff where Sam's body is still hanging from her rope from the first movie. He's later found on the bone pit, barely alive. But in the first movie, Sam's body is above a water-filled pit which Juno falls into and finishes off one of the crawlers. They'd already found the bone pit in a different location.

At around 32 minutes, while Vaines unclasps his holster and takes out the gun, his thumbnail looks completely different from the one holding the camera. The last-mentioned thumbnail lets us assume that the cameraman is a much younger person than Vaines.

Characters are carrying flashlights that are shining to the front, but the characters project shadows behind them.

At around 35 minutes, while Cath is trapped on the other side of the fallen boulders, a knee-high rock to the right of Dan's leg slightly moves as he is rescuing her.

Lighting throughout the cave system is inconsistent with the light sources used (flashlights and glow sticks).

This film is set in 2005, right after the first one. At 1 hour, 2 minutes, Rios records her video message to her daughter on a Nokia N81 phone, which wasn't released until 2007.

A few minutes in the sheriff and the old man come upon an abandoned mine and the old man says, "What is this place/" And about 5 minutes later while the team is gathering in the mine, the old then has a whole back story about how his grandpa use to work in the mine and went down in it and never came back, and yet as stated he said he had no idea what this place is.