Other mistake: The scene where Clear is in the garage, she puts the car in drive, but somehow reverses the car through the garage door. (01:24:49)
Other mistake: When the plane takes off in Alex's vision, the plane begins to go into a nosedive, and the entire left fuselage is blown apart, sucking many people out of the plane. The plane then explodes completely, but in reality, the plane just takes off, and explodes almost instantly afterwards. No struggling with the plane is shown in reality, nor is the plane going into a nosedive. This is also proven in FD5, which is a prequel. The jet engine explodes, leaving a flaming tail, and the plane spinning out of control. The plane just simply "explodes" without any signs of struggle.
Suggested correction: According to the news report, "Officials believe deterioration of silicon insulation on an electrical connector to the scavenger pump may have leaked combustible fluids. A spark in the fuel switch in the fuselage may have ignited the fuel line and proceeded to the fuel pump which would have set off the catastrophic explosion." This spark, in the premonition, happened while they were already in the air, which is why the damage occured how it did. However, in reality, Alex has his panic, and they're escorted off. So instead of already being up on the air, the spark happens as soon as the plane takes off instead. Further, when you compare the timeline of the explosion in the premonition and the explosion in real life, roughly the same amount of time has passed, placing the explosion at the same moment it should have been to start with.
Suggested correction: Death will find any way to make sure that someone dies when they're supposed to, so regardless of how it happens, how natural is it when an invisible force is causing the explosion? Plus, just because Alex had a vision of it does not mean that the real-life occurrence will happen in the same way. It doesn't really matter how the plane exploded; all that matters is that it did.
It's shown throughout the series that the visions are how the deaths take place. So the mistake is valid.
Other mistake: When Carter is basically trying to kill himself with the remaining "survivors" in his car, Billy makes a comment saying that when he saw Alex leaving Mrs. Lewton's place, Alex's shoe prints were in her blood and his prints were on the knife. All good and fine but there's just one thing that doesn't make much sense. Her house blew up right after he ran out, so could anyone still pull off any prints from the knife that killed her, and see footprints by her body? Wouldn't that evidence be gone in the explosion?
Suggested correction: Not necessarily. An explosion doesn't mean that everything around it is incinerated. Depending on where the explosion originated, certain items can be shielded from the blast/fire by larger objects, and I believe they mentioned that the fire caramelized the bloody footprints.