Continuity mistake: When Enders gets shot numerous times at the end, he lies in a crater left from a shell. He begins to cough up blood, and it drips down the left side (as we look at it) of his mouth and chin. The view then switches to one behind him, facing Ben. There is no blood around his mouth or dripping down his chin. The view then changes back to the original one, and the blood's there again.
Continuity mistake: During the end of the movie where Ben, his wife, and George are sitting on the rocks there is a visible error. In one shot the dish (in which Ben will wash Joe's dog tags) is sitting on a blue cloth. In the next shot where he actually washes the tags, it is sitting on the rock.