Plot hole: Even if boys of that age had the technical know-how to quickly repair Jeeps over 20 years old (seriously?), any gasoline in the tank would have long become unusable, the tires and lines would have rotted away, and the electrics would all be dead. Now if it was in the desert or a dry garage, it may have survived, but it's on a tropical island, in a shed that has all sorts of holes in the roof, leaving it exposed to every kind of weather the island could throw at it. In addition, the kids start the jeep with the small battery of an ATV, which cannot produce enough power to crank a Jeep engine.
Continuity mistake: The restricted zone where the original Jurassic Park was is to the north. After Indominus chases the kids to the waterfall, it is said in the control room that the huge dino is moving south to the crowds waiting for rides to reopen in the downtown section, drawn by the heat signatures of the gathered masses. A few scenes later, Indominus is up north again terrorizing the kids at the Jurassic Park jeep port.
Continuity mistake: When Zach and Gray are waiting for the gyrosphere, Zach stares at two girls and there's two more behind them. When the gyrosphere arrives for the first pair, there's no sign of the second pair. (00:49:00)