Continuity mistake: After the chase where Jo loses her truck, her pants are wet and muddy. After the flying cow waterspouts, the pants are clean and dry.
Continuity mistake: When Bill and Jo are in the truck, Jo looks at the dashboard, which is shown, and then Jo looks away and covers her eyes. Bill then floors the gas, and the dashboard is shown, and this time, the airbag light is on, unlike the previous shot of the dashboard two seconds earlier.
Continuity mistake: During a scene in the middle they drive the red Dodge solo into the hills to face a twister. As they bail out they find that they can't free the "Dorothy" from the back of the truck, so they have to run for it. As they look back they watch power poles start blowing up. Finally the one next to the truck goes and falls across the bed of the truck, smashing Dorothy onto the roadway and spilling the sensors. As they come back to the truck, because the twister has disappeared, they realise the twister is "jumping" and pile into the truck for their escape. The power pole is no longer resting across the truck and there is no damage to the bed.
Answer: No double meanings. Jo just sees the lethal-looking farm equipment (which is ordinary equipment that many farmers have) and in her panicked state wonders who would have such dangerous things in their barn, as though they were serial killers or something. Bill's "I don't think so!" just means they're not hiding in the barn where they could get impaled or decapitated at any second.
Krista