In the scene where Ahmat and Martijn are writing down the names, Laurence Fishburne's hand double uses a different pencil grip (three finger and thumb) than Laurence (two fingers and thumb).
It is not possible to read time in seconds on an analogue chess-clock. So the brute cannot know when to begin the countdown before the flag falls.
At a certain point the torturers claim that the cut off fingers could still be sewed back on by a good doctor. But that's more than 24 hours after the first finger, and thus impossible. The storing on ice is not very helpful either: the frost would damage the fingers after a short while.
When the brute starts his countdown, there are still three minutes left on the chess-clock.