Factual error: When Lara looks through the telescope, it should be dark in the room.
Continuity mistake: During the temple fight with the stone warriors, Lara us shown fighting with both her pistols. In the shots from the front, her right pistol is held lower than the left one. However, the shots from the rear show both pistols held level with each other. This happens a couple of times throughout the scene.
Continuity mistake: If you compare Lara's braid during the film and her "open" hair during the last scenes you can see that her braid is actually a bit longer, which shouldn't be possible because braiding shortens the length.
Plot hole: About Lara's getting inside the Cambodian temple, how exactly does plucking off a flower activate a mechanism that opens a secret entrance to it? (Over the centuries, none of those flowers ever withered or was plucked off by the wind, of course).
Continuity mistake: In Cambodia, when Lara spots the second little girl, her plait is over her right shoulder, and in the next shot, it is down her back.
Continuity mistake: When Lara meets Powell in Venice, his cigar switches from his left to his right hand between shots.