After Max is shot, she is given a new shirt from the girl she saves. In the next flight scenes, Max can be seen flying with the shirt she wore before she was shot.
Near the beginning of the film, the flock can be seen looking at a map in the computer room, with the company logo of the computer covered by a sticky note; however, in a later scene, the sticky note is not there and the Apple logo on the computer is clearly visible.
When Fang carries an unconscious Max to be looked at by Dr. Martinez, you can see that Allie Marie Evans is holding her head up.
When Max gets shot, you can clearly see it's in her left shoulder, but later she is seen grabbing at her right shoulder.
Not once in the movie did they mention the name of Patrick Johnson's character (Fang). Anyone who did not read the book wouldn't know his name.
When Max and Fang go to Moab, Utah (as displayed on screen), the establishing shot is actually of Salt Lake City, Utah. The Church of Jesus Christ of Latter-day Saints (Mormon) temple and downtown buildings are clear giveaways.
The scenes at the cabin on Lake Mead have large pine/evergreen trees. Nowhere along the shores of Lake Mead are such trees in abundance as they portray in the movie. The shoreline of Lake Mead at the filming of the movie would have been much lower than the historical normal water levels of the lake, leaving several feet of bleached out and discolored shoreline. The scenes are obviously not at Lake Mead.