In the "Goodbye" episode, and several others over the first three seasons, Finn holds a picture of and looks at his father in a uniform which clearly has "U.S. MARINES" sewn on it, yet Finn and his mother repeatedly speak about his father as a Soldier in the U.S. Army. While Finn's father may have been a Marine before joining the Army, the writers should have had an actor in an Army uniform for the pictures, not a Marine uniform.
None of the people in the photo collage in Rachel's locker are characters previously seen.