(at around 22 mins) Shilah (Noree Victoria) gives Paula (Bre Blair) a shot in the plane after she is bitten, saying that the shot is lidocaine and is a sedative. Lidocaine is actually used as a local anesthetic and as an antiarrhythmic drug, not a sedative.
(at around 36 mins) Some may believe that the character Nial, illegally brought a gun on the plane. However, while it is illegal to bring a gun on a plane through carry-on, the Transport Security Administration (TSA) allows firearms to be checked in a locked hard container. Firearms must also be unloaded. Since Nial's gun was checked and unloaded, there is no goof.