One of Rory's Yale professors, Professor Bell, played by George Anthony Bell is seen later as a Stars Hollow resident Knit, People, Knit! (2006), and again as a court officer To Whom It May Concern (2007). He is listed in the credits for both the Season 7 episodes as Professor Bell, though he CLEARLY does not play Professor Bell.
Lorelai discusses Luke's "dark day" with a few different people no one seems to know the reason behind it. Some of which (Miss Patty and Kirk) have known him since he was a child and knew his father. Considering this and how small the town is, it seems odd that no one seemed to work out that the "dark day" was on the anniversary of Luke's dads death.
Any call made to the headmaster of a prestigious school like Chilton would go through his secretary, yet when Rory returns his call she is directly connected to him.