- Critical Dissonance: Based on the Rottentomatoes score, those categorized as "Top Critics" were much more likely to give the film positive reviews. This was also the case with Clint Eastwood's previous film Hereafter.
- Funny Moments: Richard Nixon's heartfelt impromptu eulogy for the newly deceased Hoover. "That old cocksucker!" Truth in Television, amusingly enough.
- Magnificent Bastard: Hoover. Brilliant? His FBI is the first law enforcement agency in the U.S. to focus on forensic evidence such as fingerprints. Check. Devious? He keeps secret files on all his political rivals. Check. Smooth operator? Some of his hearings before Congress draw applause from the gallery. Check. Has a goal? Two actually, the success of the FBI and his own fame. Check. Charismatic? Gets a peck on the cheek from Shirley Temple and is invited to dine with Ginger Rogers.
- Retroactive Recognition: Adam Driver makes his first ever film appearance as Walter Lyle, the gas station owner who directs the FBI to Bruno Hauptmann.
- Special Effect Failure: The age-effect make-up used throughout the film is surprisingly ropey — Tolson especially looks ridiculous, especially in the harsh light of day during the races scene, with his over-done age-spots and an overall look that suggests a rubber head, rather than clever use of make-up....
- WTH, Casting Agency?: Leonardo Di Caprio as Hoover is a clear case of Ability over Appearance. He does well but he doesn't look a thing like the real guy.
YMMV / J. Edgar