When Russell is about to be interviewed in William's room, a shirt is on the chair Russell sits on. He turns the chair around and throws the shirt on the floor. In the next shot, the shirt reappears on the chair.
When William is sitting in the bathtub, Penny Lane comes in to use the bathroom. Startled, William knocks his notes off the edge of the tub. In the next scene, the notes are still lined up on the edge of the tub.
When William drags Penny Lane across the floor as she's ODing, the soles of her bare feet are dirty. When the doctor and nurse pump her stomach in the bathroom, they're clean.
In the Bootleg/Untitles cut when Lester Bangs is interviewed at the radio station, he picks the Yes' album "Fragile" from the shelf, says "Yes? No !", and throws the record on the ground. When he then picks another record, "Live American Woman", and "Fragile" is back on the shelf.
In the theater/cinema cut the "Yes? No!" sequence is missing but "Fragile" disappears from the shelf behind Lester.
In the theater/cinema cut the "Yes? No!" sequence is missing but "Fragile" disappears from the shelf behind Lester.
When William Miller and Russell Hammond are walking outside
the concert, a VW bus is driving behind them and passes them on the street. In the next shot, the same VW bus is back 50 yards or so again. It then passes by again less that 10 seconds later and the driver invites Russell and William to a party.
One of the stops on the Stillwater tour is Greeneville, Tennessee. The movie spells it "Greenville."
When William is writing in the tub and Penny Lane walks in, Post-It Notes appear to be all over the tub. Post-it Notes were invented in 1977, and not released to the public until at least 1979. In the DVD commentary for "Untitled", Cameron Crowe says the notes are folded yellow legal paper.
Throughout the movie, various albums and tracks are mentioned, heard and seen, even though they weren't released at the time the individual scenes are set. However, they are "of the period," and suit the scenes for other reasons.
Elaine, a professor, says she's going to give someone the "Cliff Notes" version, instead of the correct "Cliffs Notes" (or, as originally spelled, "Cliff's Notes"). However, the study aids have almost always been colloquially known as "Cliff Notes;"; the fact that they are incorrectly referred to as "CliffNotes" is even mentioned in the "CliffsNotes" Wikipedia entry.
When William is typing his first article, the words, "And it's not about popularity" are appearing on the paper, but he is typing T G U G H M R and N.
On the bus, when Sapphire tells William about his mother calling, she braces herself before she hits the wall.
When the tour bus passes a group of high school girls jogging, Penny waves to the girls first from the passing bus, which makes the girls wave back. A moment later she extends her middle finger to them which makes the girls vocally react. Unless the bus was passing by them at a crawling speed, it is impossible for the girls to see Penny's waving turning to a middle finger at a bus moving that quickly on the road.
When the sister leaves at the beginning, she puts on Paul Simon & Art Garfunkel's "Book Ends" album to play "America." We hear the song begin crisply, but on that album, "America" fades up as the tail end of "Save the Life of My Child" is fading out.
When "Sparks" plays on the turntable, the camera shows side 4 of the vinyl record turning. "Sparks" is on side 1, on the flip side of the record.
At the Black Sabbath show where William first meets Stillwater, someone backstage wears a 1997 Black Sabbath Reunion "Devil Twins" T-Shirt.
As William Miller and Lester Bangs prepare to part ways on a street corner, several modern-day vehicles, including a recent San Diego Transit bus, are visible beyond the trees.
William Miller appears in underwear with the "Fruit of the Loom" name printed all around the waistband. That style was first produced in the 1990s.
Estrella says "Simon Kirke from Bad Company is by the pool". Simon Kirke's band did not use the name Bad Company until November 1973, and their first album did not debut until 1974.
Penny Lane rides a plane with winglets. The advantages of winglets weren't proven until 1976, and they were first used on commercial planes in 1985.
When William goes up to Russell in the pool and asks him a question with his recorder, his lips aren't moving.
During the storm, the plane's engines are not audible, as if they were shut down. When the engines whine up again, the piston engines have acquired turbofans.
William is standing in the hallway at the live Black Sabbath show, but the song played in the studio version of "Sweet Leaf".
William's mother incorrectly, when scolding Russell on the phone, attributes to Johann Wolfgang von Goethe the saying; "Be bold and mighty forces will come to your aid." This quote is actually by Dorothea Brande. Brande herself likely was paraphrasing a passage from a book by Basil King. ("Go at it boldly, and you'll find unexpected forces closing round you and coming to your aid".) King was a Canadian clergyman who became a writer after retiring from the clergy.
On the bus when everyone is singing "Tiny Dancer", William says something to Penny. Penny already had her mouth open to sing the next lyrics "Hold me closer." However, the next line is actually "Count the headlights on the highway."
Lester Bangs, in his first chat with William, talks about when he used to write while taking cough syrup and speed, and he calls what he wrote "dribble". While the correct term is "drivel", using "dribble" was a common play on words, since dribble is spit leaking out of your mouth. A similar play on words was using "bad altitude" instead of "bad attitude", meaning someone who thought they were above everyone else.
Lester Bangs, in his first chat with William, talks about when he used to write while taking cough syrup and speed, and he calls what he wrote "dribble". The correct term is "drivel".
William tells Lester Bangs that he uses a "Smith Corona Galaxis-Deluxe" typewriter. This seems either a misspoken line or a misspelling; the correct name of that model is Galaxie-Deluxe.