Other mistake: Although the film is set in Oklahoma (and north of Oklahoma City), the roads are marked by Texas road signs.
Other mistake: After the last tornado that passes directly over them, of F5 intensity, immediately afterwards, Helen Hunt still has her lightweight headphones casually draped around her neck. A stiff breeze could have blown them off, but not an F5 tornado?
Other mistake: When Paxton and Hunt are in the shed at the end attaching themselves to the water pipe with the straps, there is an above shot looking down at them. If you look outside the window you can see corn husks barely moving on the ground despite there being an F-5 right outside.
Other mistake: During the garage scene, we see a large neon sign get ripped off of its mounting pole and thrown into the garage. It seems obvious that the sign is no longer connected to any sort of electricity source, however, the sign stays lit as it is ripped off its pole, into the next shot when it crashes into the garage, and then it continues to flicker a bit as it lays on the ground.
Other mistake: The first time we see the NSSL; the woman's name there is Chris. Later in the movie, when we see the NSSL again, her name is Bryce. Turn the captions on so you can tell.
Other mistake: In the scene in the garage pit, one of the characters is hit in the forehead by a flying hubcap. He is cut clear across his forehead, but there is only a small trickle of blood oozing from the wound. I've seen many scalp lacerations and even the most minor ones will bleed like a stuck pig, where's all of that blood?
Other mistake: When the twister hits the drive in theater, the sirens are wailing, but nobody reacts. Only when Jo screams at the waitresses they start panicking and run. The movie is set in Oklahoma, smack in the middle of tornado alley. The people there know what the sirens mean, they sure don't need no out-of-town big-shots to tell them to get under cover.
Suggested correction: Sirens go off so many times that true Okies tend to ignore them. We might get nervous if the cable goes out.
Do true Okies also run screaming the second an out-of-town big-shot yells at them? Sorry but that argument just doesn't compute. People ignoring fair warning simply isn't a thing in the movie. The main plotline is people not getting warnings soon enough.
It's also possible that they did hear the siren, but unlike the people at the drive-in who could actually see the tornado tearing the screen apart, the people at the snack bar might not have been able to see it (especially with an awning over the windows). They were probably at most confused as to what was happening and it wasn't until Jo actually said to get underground that they realised it was real and was actually happening.
Other mistake: When Bill and Jo are strapped to the water pipes in the final twister scene, after the tornado passes and they are back on the ground, one of their leather straps are already broken. In this condition it never would have held itself on that pipe, let alone an average sized human being.
Other mistake: When the Tree gets blown under the red truck and they get stuck on it. Why don't they ever put the truck in 4WD? You can see the front differential and 4x4 markings so the truck definately HAS 4WD. That particular year of truck doesn't even require you to get out and lock the hubs.
Suggested correction: Character mistake more than anything. In a panic situation you don't tend to think of the obvious solution. The other issue to is that even if the truck was in 4wd that it might not have been enough. Keep in mind that the rear tires did burnout on a few attempts so the issue wasn't that the wheels weren't stable on the ground but that the tree trunk might have been too big to get the wheels over it by driving across (especially from the angle they were at).
Other mistake: When Jo readies Dorothy IV on the back of the truck, she switches it on, but she never releases the rubber catches holding the lid in place.
Suggested correction: The rubber catches weren't needed to open the machine; they were only there to secure the entire lid in place. As seen when Jo is first showing how Dorothy works, the lid could be opened manually or automatically, depending on which button you pressed. As long as the pack was "set up" (sirens on and buttons activated), the pack would open automatically when close enough to the tornado, as shown when the pack lid opens at the end.
The way I understood it, the rubber catches were there to secure the lid in place during travel and had to be released for the automatic opening mechanism - the existence of which you are entirely correct about - to open the lid. That makes sense entirely, if you are bouncing over rough terrain, you would not want to load gears or servos with the considerable force spikes thick acrylic panels would impart on them were they not otherwise secured.
Other mistake: The order of action performed to activate Dorothy 2 (jumping tornado scene) and 4 (F5 tornado scene) is reversed. Also, Bill somehow has more switches to flip. Jo pressed a button, flipped a couple switches and then told Bill Dorothy was ready, while Bill had to flip the same switches, then flip some more, then press the buttons before starting to unstrap the device from the truck. (Jo didn't have to unstrap D4 because they realised at that point it had to be anchored to something heavy because the device was too light and decided to sacrifice the truck). However it is possible that Bill actually flipped the same switches twice. We can see him flip the switches, then we have a quick close shot of Dorothy 2 then the camera goes back to Bill flipping the switches again. There is no such angle change during the part where Jo activate D4, so it's very much probable that they got two angles of Bill Paxton flipping the switches, but forgot to cut one. (00:59:15 - 01:36:00)
Other mistake: In the garage scene just as the neon sign collapses almost onto the storm chasers, the scene plays twice when the sign lands near the storm chasers who are taking shelter in the garage pit.
Other mistake: Less than a few minutes into the film, there is a shot of a dark sky looking through a barbed wire fence with yellow wildflowers at the bottom of the frame. The flowers start blowing in the wind, and then snap back to the beginning of the shot. Just before the shot cuts, the wildflowers move again, repeating the action earlier. The shot is looped.
Other mistake: During the movie, some characters wear a headset to communicate (Rabbit, Joey, Dusty, Jo, Jonas). Nothing wrong there, but they also use the CB radio/mic in addition to using the headset. And it's not so they can hear conversations better, since Rabbit and Jonas use the mic on their headsets 99% of the time. There are also instances where you can hear conversations from some of these characters when they don't use the CB radio, so the only mic that makes sense is from the headset.
Other mistake: How come it's the sunniest day ever a few feet from an F5 tornado?
Other mistake: While in Wakita, in northern Oklahoma, the crew see the report of the F-3, and it was 30 minutes away. They meet the tornado in Texas, several hours away.
Suggested correction: The tornado is actually 30 miles away, not 30 minutes. Quite a difference for time.
Other mistake: Near the end after Bill and Jo have jumped out of the truck, their crew sees the truck and Dorothy go up in the tornado, they are receiving telemetry, then one of them notices the tornado shift direction and the crew still tries to notify Bill and Jo by radio, knowing they're no longer in the truck nor have radio communications.
Suggested correction: Jo still has her headset on. The crew can probably communicate with her that way, but she may not have been able to hear them since they were so close to the tornado in the cornfield.
