Continuity mistake: After 70 days in the Andes, Nando has not grown a beard. Two days later, when they come with the choppers, he's managed to grow quite a nice one.
Suggested correction: It's possible that Nando continued shaving (offscreen) while they were living at the plane, but gave it up (or left his razor behind) during the trek out of the mountains. In real life, some of the survivors did shave while in the mountains.
Continuity mistake: In the scene when the expedition of 3 finds the tail of the plane you can see an extra set of footprints in the snow when the team arrives. Who was the 4th person walking to the tail?