Continuity mistake: After beating the lake monster Del Lago and going through the cutscene and chapter end, you can take the boat out on the lake. When you come up to a dock, you can bring the boat up to either side. The cutscene always shows Leon pulling the boat up to the same side of the dock, regardless of which side you chose beforehand.
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.