Where Freddie returns from the hospital, we can see the numbers from Miranda's calender on the wall in several shots. She had painted over the numbers to mark the passing of time earlier in the film.
By the fireplace, Freddie's shirt changes from unbuttoned to buttoned awfully fast.
When Freddie is trying to silence Miranda when she is in the bath, the cones covering her nipples can be clearly seen.
You can call Freddie "Lightning" because of the speed he can change his socks. When he and Miranda agree on the four weeks, we can see that in the cellar Freddie has brown socks on. But right after that when he sits down in the garden, his socks are blue.