Goofs

David took a 12 volt/6 cell battery out of the 1970s Chevrolet Blazer, and replaced it with a 6 volt/3 cell battery. A 6 volt system can usually be used with a 12 volt battery in an emergency, but not the opposite.

At the 34 minute mark, the Daughter, Debbie, calls the woman they find "Jenny" before they actually find out the woman's name (they discover this at the 56 minute mark).

During the earthquake as they run out of the cave several large boulders fall in their path, as Deborah passes one she easily pushes as aside, and as Steven passes he leans on it with one hand which causes it to squeeze down, showing the it is clearly made of foam rubber.

The "dust" that the afflicted turn into doesn't seem to contain fillings, dentures, surgical pins or any other metallic parts that aren't part of the human body, but are inside of it,

In the second to last scene, it is stated that it is "almost morning", but when running on the beach, shadows are pointing to their left. As Malibu faces the ocean to the south, that means their shadows are pointing east, meaning it's the afternoon. Also, the length of shadows changes dramatically between shots of running from the house to the beach.

Driving from central California to Malibu, they pass through Los Angeles. Malibu is Northwest of Los Angeles, and one would assume they would take the most direct route there - avoiding the city as they were warned from a previous encounter with a survivor.

The family was camping in Central California did was trying to get to Southern California (Malibu, in particular). That distance shouldn't have been more than 350-400 miles AT MOST and with vehicles should taken 1-2 days at most. Since the roads weren't shown to be clogged and they wouldn't have had to compete with much traffic, once they got on the road, they should have been home later that day or early the next,

In the letter left by Barbara, she says protection from the solar flares is inherited via a gene which is "probably recessive". For children to inherit a genetic attribute possessed by only one parent, it would have to be dominant, not recessive.