Factual error: In the scene in the basement during the storm Dale is running the projector on house electricity. The lights go out and he switches to a battery which must be 12 volt. He runs the projector on that current, which is impossible.
Factual error: There are actually no dinosaur remains at the British Museum. There used to be, many many years back, but they were removed to the Natural History Museum, which is about 3 miles from the British Museum.
Factual error: Ryan Reynolds has an entire trailer of evergreen trees that he is going to plant in the middle of the winter. No landscaper would plant trees at this time because the ground is frozen, and if planted they would die.
Factual error: Roland enters the train to go to the war, in 1914, with "Spanish Flu", but that was the (wrong) name given to the 1918 flu pandemic, which lasted from spring 1918 through spring or early summer 1919.