Other mistake: Throughout the saga, blood has been shown as essential for vampire's healing factor, and Selene herself used her blood to heal people. Somehow, this time around neither her or her pal David think in any way of this basic fact, making a complicated trip to the vampire doctor necessary, who simply feeds the vampire kid some blood, the very first thing any vampire would do to regain strength.
Plot hole: Selene has been kept in a cryogenic tank for 12 years. And for 12 years the scientists running experiments on her very conveniently kept her boots and skin tight suit in the lab. Not just that: they did not keep them in a locker or in a box, but scattered across different shelves of the glass cabinet where they also store test tubes and big bottles of chemicals. Directly in front of them, in fact. (00:10:00)
