Carbon dating?
Watching this right now. I don't know if this was brought up before, but the line early on about the Confederate bullion being used in an arms deal -- they said they knew the gold was real (stamped 1863) through carbon dating. But that wouldn't work, because the gold was brought to the present day instantaneously, and thus would not have aged.
I know, time travel movies are full of these kinds of errors. I try to let most of them go, but this one jumped right out at me.