Other mistake: To retrieve the bird whistle in Miriam's apartment, Thadd fills the vase it ended up in with water, using either the glass or the mug from the bar. The game makes you do it twice, because only once would not suffice. Too bad that the vase is so big that it gets to George's chest (you can't pick it up because it's "too heavy", as he comments), so 2 little glasses would never be enough to fill it, and to the brim even.
Plot hole: The main character finds the dead journalist at the beginning of the movie, walks back to town using the main road, and when he gets there not only have the police found the cadaver already, but the barman knows all about it, including the outcome of the questioning of the witness. Stellar police work and mad gossiping skills, all without the police cars passing by the unsuspecting Thad and arresting him.