Factual error: It is impossible for a stream of burning jet fuel to follow a plane through snow and catch up. Not only is jet fuel extremely hard to ignite, almost as soon as the plane was off the ground the fuel stream would be too dispersed for the flame to climb up into the tank, and even if not it wouldn't burn fast enough to catch the plane.
Factual error: When Kevin's mom leaves Paris to return home, the plane shown departing the airport is a DC-9. No airline uses this plane for trans-Atlantic service - it doesn't have the required range.
Suggested correction: Although not explicitly mentioned, it could be a connecting flight which departs Europe from another airport. In this case, flying a short or medium range aircraft to reach a hub airport like Heathrow would be plausible.
They stopped at an intermediate airport to catch a connecting flight and still nobody noticed Kevin was missing? Absolute rubbish. The posting is absolutely correct.
This is a mistake on the trip home, by which point they already noticed Kevin was missing. They had a non-stop flight going there.
Nonsense. With a maximum fuel load, the DC9 had a range of 1450 nautical miles (2685 km). If they stopped to refuel at Shannon airport in Ireland - which is closer to New York than Heathrow - they would still have to fly 2878 nautical miles (5330 km) to reach New York. They are going for a very long swim.