Toward the end of the movie, while they are taking shelter in the storm drain, the same manhole cover blows off twice.
When the buses and cars are fleeing the EF-5 tornado, in one shot out the windshield of the bus Gary is driving shows he is following other buses. After one brief interior shot the next shot out of the windshield shows only cars ahead and no buses although you can see far down the road.
The blue van is a Dodge Sprinter on the outside, but a Freightliner Sprinter on the inside.
When Allison and Gary arrive at the mill, Lucas is seen exiting the van but then disappears but reappears in the Titus with everyone on the way back to the school.
When Gary and Trey are driving into town the tornado is over a block away in front of them. Then when their SUV spins out they appear to be right in the middle of the tornado, but after they crash and head for shelter in the bank the tornado appears to be over a block away again.
At the end of the movie in the drain the wind blows in the same direction before and after the eye. After the eye the direction should be reverse.
In several of the tornado scenes the tornadoes are strong enough to blow vehicles and large debris around, but the people seem to be able to move around in the same winds without much difficulty.
When the first tornado to hit the Silverton area forms, Allison waits until it is on the ground for several minutes before calling in the tornado warning. Any professional storm chaser would have called the warning in right when the wall cloud formed, or at the very least at the first sign of the funnel as public safety would have been more important to them than observations or photos/videos.
When the two tornadoes spin up in the downtown scene with the amateur storm chasers, the second tornado immediately contains debris, presumably from scouring the asphalt, a tornado that newly spawned and of that magnitude would not have scoured asphalt. For a tornado to scour asphalt, it would typically be rated EF4 to EF5 (especially EF5) on the Enhanced Fujita scale.
Windshield wipers on the armored storm chaser vehicle function normally although we are told there are 300 M.P.H. winds with the Cat5 Tornado.
Sparking high-voltage power lines on the ground. This would not happen for lines of this type as circuit breakers would instantly disconnect the power.
When two kids are trapped in a building, the water rising, a chunk of "cement" bobs in the water when one of them moves.
After the EF5 tornado forms and the crew is driving towards it in town, a cow sign is seen blown off the top of a building even though it's not even close to the tornado's circulation.
When the school is evacuated, either all the buses have had the keys left in them, or everyone conveniently happens to be carrying the key for the bus they choose - both highly unlikely.
The time displayed through the school's surveillance cameras are completely unrelated to the current time of day.
Considering this takes place in Oklahoma, residents would take seriously any threat of massive tornado threats. If the meteorologist in the van knows it, surely the weather bureau would know it too. There is no way the school would plan an outdoor commencement ceremony on an afternoon that offered such potential for extreme damage.
It is entirely likely for a school commencement to be located outdoors on a day that a tornado ends up hitting. School commencements tend to have their venue chosen weeks to months before the commencement takes place while a tornado tends to be forecast less than a day before the tornado hits thus there would be no way for the commencement organizers to know that a tornado would hit the commencement venue on the day of the commencement when they are choosing the location of the commencement.
Daryl says that they have to forecast tornadoes before they start hitting "places they have never hit before such as Chicago, Los Angeles, even London." The Chicago and London area have been hit numerous times by tornadoes over the years, and the L.A. area has also had some tornadoes albeit usually smaller and weaker ones or waterspouts that move inland. A seasoned storm chaser would have known this and used better examples.
While driving with Allison to save his son, Gary has the cell phone to his ear and says, "There is no signal." You see no signal by looking at the phone not listening to it.
Trey tells Donnie he sees himself playing lead guitar for 100,000 people at Madison Square Garden. The maximum capacity for a concert at Madison Square Garden is 20,000.