Trivia: The dramatic pause, as the taxi hits the gate near the end of the film, is done so because this was the original ending. Test audiences didn't like the ambiguity of the ending and wanted something more succinct, and so we got an ending-like sequence followed by the actual ending.
Trivia: Mark was likely not infected. The wound on his arm was clean-cut and probably from either glass or a weapon wound. A bite mark would look very different. It is likely that he asked Selena to wait because he was scared and knew what she was like.
Answer: That question is actually answered. The pilot is speaking Finnish, and he says into the radio "lähetätkö helikopterin" which translates as "Can you please send a helicopter?" Looks like he was actually helping them after all, and there is still some civilization (or at least people with radios and helicopters).