Continuity mistake: As the gang drives towards the cave entrance, the spare wheel on the back of the car that Sarah is driving switches sides three times. (00:16:30 - 00:17:10)
Continuity mistake: Right near the end of the film, one of the characters is driving away from the caves and eventually pulls over onto a grass verge where she breaks down in tears. Seconds later, a lorry carrying logs drives past her sounding the horn. At this point, you can see that her vehicle is now on the road.
Continuity mistake: When they are crossing the first drop, as the second girl is crossing you can see two people on the right hand side, when there should be only one.
Continuity mistake: When the girls are crossing the first chasm over the huge drop, the first two girls make it to the other end safely using a wire. When the two girls are hooking up the third girl to come across, we can see four people stood behind her. There should only be three.
Continuity mistake: When Sarah falls into the pool of blood, the torch falls behind the big rock to her left. In the next shots, the torch is on the top of the rock. (01:14:05)
Continuity mistake: The license plate on the front of the car that Sarah "escapes" in at the end is on the left hand side. But in a brief shot of her driving the car over a jump, the license plate suddenly switches to the right hand side. It then returns to the left hand side. (01:32:20)
Continuity mistake: Right at the end where we see Sarah still in the cave with her daughter and her birthday cake, the number of candles on the cake changes from 5 to 6 between shots.
Answer: She does escape, as seen in the Descent Part 2.