Factual error: All propane tanks for the last 30 or so years have a safety valve which prevents them from simply releasing gas when the valve is turned on. Given these tanks looked brand new and Jake only turns them on, the gas would not have been released.
Factual error: When Mr Goodman is telling Julie "no one release this piranha into the lake", he states that pygocentrus nattereri is "the original piranha, they used to swim the Colorado River right up until the Pleistocene epoch, I still don't know how you found one...alive!" The pygocentrus nattereri is a species of piranha native to South America, very common, not even on the endangered species list. (00:43:10)