Behind Enemy Lines - Winter to Summer
About a half hour through the movie, in the scene where Owen Wilson sits down on a huge cement wall, possibly a dam, for a drink, right before the sniper takes shots at him, you will notice all the trees behind him have leaves on them. The movie is supposed to be set in Bosnia in the winter. All the rest of the scenes are consistent with the movie being set in winter.
Copy of 'Behind Enemy Lines'