When Professor Fowler is looking out the window listening to the singers, he is wearing glasses in some angles and not wearing glasses in others.
When Professor Fowler brushes the snow from the tombstone, you can hear a hollow sound, indicating that the tombstone is made of plastic.
Professor Fowler recognizes Dickie Weiss as "the first" one of his former students to die, on the USS Arizona at Pearl Harbor on December 7, 1941. However, he then meets another former student, Rice, who died during the Battle of Château-Thierry on July 18, 1918, 23 years earlier.