Continuity mistake: After Leon beats Bitores Mendez and takes his fake eye, you will notice if you look closely at his corpse that his fake eye is still in his head.
Trivia: After leaving the main menu of RE4 for about 20 seconds, the trailer for the game comes up. During the course of the trailer, there is a short scene of Ashley putting her head in her arms. This is a reverse of a cut scene in the game where you rescue her after fighting the Iron Maiden, in which she looks up to see Leon.