Factual error: When Yuri is narrating about selling weapons for the US government (this was around the scene when he sells M-16's by the kilo), he mentions Lieutenant Colonel Southern. However, when you see the him, he has Colonel rank, which is a silver eagle. The Lieutenant Colonel rank is a silver leaf, not an eagle.
Character mistake: Nic Cage says "At 4 and a half months, the human fetus has a reptile's tail". This is totally incorrect. A human fetus has a tail-like structure between 4 and 7 weeks, not months, and it is little more than a mass of flesh which helps the muscular structure of the backbone develop before being absorbed for use in the formation of the legs and hips. (01:28:50)
Continuity mistake: When Ava is in Yuri's trailer discovering all the guns and things, Nicolai is shown behind the blue things hanging from the ceiling. It cuts to a close up of Ava, then it cuts back to where you can see where Nicolai was standing, but he is gone. It cuts back to Ava and then back again, and he is there.