Revealing mistake: When Elle and Emmett are talking on the benches, a girl in a blue-gray shirt and red tie leaves the building twice.
Suggested correction: It's entirely possible that this girl just re-entered the building through a different entrance and left again.
Factual error: In the final graduation scene, the faculty members on the stage are all wearing mortarboard caps. In fact, they should be wearing the traditional "doctors" graduation caps which resemble Scottish tam-o-shanters.
Suggested correction: Faculty should be wearing the cap and gown of the institution they graduated from, which may or may not be Harvard. I do not teach at the university I obtained my doctorate from, but at graduation I wear the robe and hat from where I earned my PhD, not the one of where I teach as I earned no degree there. That is how it works in the USA. The graduates will all have the same robes and hats, but not the faculty. Faculty hats will depend on where they graduated from. Mine is a standard mortarboard and my husband's is a tam as we went to different schools.