When Hushpuppy's dad poured drinks for him and Hushpuppy, he placed the plastic container cup in front of him and a cup with handle for Hushpuppy. Hushpuppy is seen drinking from the cup with handle, but the next shot her dad is drinking from Hushpuppy's cup, and then the next shot is the plastic container cup, then the one with handle again.
Hushpuppy's father, Wink, is removed from "The Bathtub" and taken to a medical clinic after the storm. While at the clinic, he is obviously sick, and told he must undergo medical treatment to live. Wink refuses the treatment, and is physically restrained by the staff. Later, he is administered painkillers or sedatives to calm him down, which he rejects. In the United States, where this film takes place, an adult citizen has the right to refuse medical treatment. No American doctor or nurse in his or her right mind would ever physically restrain a patient after being informed the patient has declined medical attention. Wink has every right to decline treatment and walk out of the clinic. He also has every right to sue the medical staff for 10 million dollars for the medical treatment he has refused, not to mention assault, and he would almost certainly win that case.
During the height of the hurricane scene, Wink challenges the storm, with his rifle, as a means of comforting Hushpuppy and alleviating her fears. While he is outside in the hurricane winds and rain, only the trees in his immediate vicinity are violently moving. Trees in the background (perhaps beyond the reach of a wind fan) are perfectly still.