He point of giving letters to the court of character is to try to reduce the sentence. If people are able to give statements with no cost, irrespective of truth or repurcuasions, then they become pointless as all would be glowing and positive. Anyone giving such a letter should be able to stand by it. If they can't they shouldn't give one.
I haven't read his letter, but I assume it talks about his time with him filming when he was younger. It doesn't seem relevant of it's about his character, aside from rapes. So, what's the point of providing it? If it is relevant, then we should question the relevance and motive and veracity of the whole purpose is to reduce the sentence of a convicted rapist.
People will all move on. However, moving on does not mean ignore and forget.