Part of the adventure is set in "1 million BC" and involves a battle against a dinosaur-like creature. But the dinosaurs (and any similar giant reptiles) were wiped out long before then (approx 65 million years ago, unless you count birds as dinosaurs). By 1 million BC the "big kahuna" on land would have been a mammal.
When the travelers arrive in the past, Dr. Swain reports their location in time as 1,000,000 years BCE, in the "Pliocene period". There was a Pliocene epoch, but it was from 5.332 million to 2.588 million years before present, considerably earlier than their supposed location. While there is fossil evidence for very large insects and arthropods in the Carboniferous period, giant bees are not part of the fossil record; the largest known relative of bees is a winged ant that could reach a length of 2.5" and lived about 50 million years ago. The Pliocene epoch was part of the age of mammals, and well-known fauna of the time included elephants, armadillos, saber-tooth cats, and the human ancestor Homo Erectus.
At the start of the show at the time tunnel, Raul Nimon shoots a revolver equipped with a silencer. However, while a silencer can work with a pistol, it cannot work on a revolver. Revolvers have a small gap between the cylinder and the barrel of the gun, which is enough to allow the gunshot noise to escape when the revolver is fired.
Doug tells Volkar that the Masters are "2 million years from here" (1 million years in the past to 1 million years in the future). Although the scientists in the time tunnel complex know that Doug is 1 million years in the past, Doug has not been told this and therefore would be incapable of making such an exact statement.