Audio problem: In the scene where the Prince meets up with Leonardo da Vinci for the first time and notices that his guards have found him, he says 'Oh, I can't believe this'. His mouth isn't in sync with what he's saying.
Suggested correction: Firstly, the closed captioning reads, "God, I don't believe this." Second, Henry actually says it twice - the first time his mouth IS in sync with what we hear, but then he mouths under his breath "I don't believe this," again, in annoyance with the situation.
I am watching the scene right now, and his mouth really isn't in sync. In order for him to say the word "believe" (even in mumbled form), he would have to move his mouth to form the "b" sound, and he does not at that point.