One of the missing persons fliers on the bulletin board outside the GCPD interrogation room is for Katharine Day. Katherine Akiko Day is in the art department for the series. The other flyer is for Kyle Davis, a fictitious author and journalist whose name appears in several episodes.
The scene where Lee wakes Riddler up is very similar to the scene in Ferris Bueller's Day Off (1986) when Sloane wakes up Cameron after he tips into the pool.