At 01:02:00, when the gang members are asleep, a gun leaning against the plane. But a few seconds later, one of them is holding that gun while still sleeping.
Treatment for snakebite is to get into a position that keeps the location of the bite below the heart. You are NOT supposed to cut the wound, especially not through clothing, which might contaminate it with fibers. Even under duress, the main character is a doctor, and should know this.
A lion pride is composed of one adult male lion, and a group of females, NOT multiple adult males. Young male lions leave their home pride to form groups of their own, or they are driven out by the alpha male. Adult male lions would never tolerate each other in the same pride.
After Andrew and the pilot kill the two gang members, the gang's car is left behind. It wasn't broken, and one of them must have had the keys, but Andrew and the pilot set off on foot rather than taking the car.