When the diary pages are first shown from Hawk's perspective, the third page from the left shows the text containing the sentence "I know who it is". But when Hawk later gives that page to Sheriff Truman, he flips the page over so that Truman can read the above-mentioned text. That is, the diary page was flipped between the two shots. Had it not been flipped, the text on the other side of the page would have been visible.