Factual error: During the big sacrifice scene an eclipse happens. An eclipse occurs when the moon passes between the earth and the sun. Later, apparently that night, the night mood is set by a shot of a full moon. The moon cannot be full until fourteen days after an eclipse, when it is directly opposite the sun.
Factual error: Given they seem to be so close (it takes him less than two days to get home) and so aggressive, it seems unlikely that Jaguar Paw's people have no knowledge of the existence of the Mayan city. Maya settlements at that time were widespread, with communities scattered widely around a political center.