The flashlights still worked, remember? He grabbed all the batteries and junk. So, maybe the camcorder used a special type of battery that survived the EMP. Also, in a real EMP, not literally every single thing would shut off. It's more like 90% of things shut off.

Also, one reason there are so many "plotholes" is because of the brilliant writing, when you think about it.

The writers writes the movie giving us only the information that the character knows. It's as if we're there, and we're living through it. We're confused about how it all happened and why it happened, and we're getting all sorts of crazy theories from random people and stuff like that. It never even says what planet the aliens came from.

This is all brilliant work on the screenplay writers part, because it's as if we're being put in the middle of all this. We're just as lost and worried and confused as the characters are.

Also, the movie really is all about the same thing the book was all about. Well's wrote the book as a way of showing how horrible and terrefying it is to be invaded and attacked by a larger, stronger force. The basic underline of his book is that war is bad.

And this movie really gives off the same feeling. When you're sitting there watching humans stoop as low as to crush a little girl and cut their hands trying to rip through a windshield, it really makes you step back and think about things.