Audio problem: When Michael Shannon fires his gun, you can hear bullet casings falling to the floor, as is normal with a semi-automatic pistol. However, his gun is a revolver, so the casings won't eject until the gun is opened and emptied manually before reloading. (01:07:10)
Factual error: While featuring a brand-new 1962 Cadillac, a 1963 Chevrolet and 1963 Ford are shown.
Factual error: Amazon rivers have no high salinity as shown as necessary to maintain the creature.
Answer: Yes, clockwork timers were invented in the 1920's. This sort of egg timer was in heavy use by the 1960's.
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