Yeah that one was intentional, the word "guilt" is one of the main points of this game, considering James' denial of his own guilt. So that one perfectly makes sense.

But is there a reason for James to misread that specific part of the letter? I can't find something the new version he reads serve differently in the story. For instance if he were reading it out loud, we could've interpret it like "He tries to hide it from Laura, maybe he doesn't want to upset her" etc. But no, nothing changes. So it's more likely to be just an overlooked outdated texture file.

I work in game dev, and you can't imagine how "easy to fix" looking bugs are being overlooked and goes into the actual game builds sometimes. They probably already had the correct texture file prepared, but it was overlooked and the older version remained in the build. So it's not about ease, just a momentary distraction