Tommy's eye color changes from brown to blue when he grows up at the end of "Christmas".
When Frank Hobbs signs the cheque for Quackson, the signature is at an angle of at least thirty degrees to the horizontal. When he hands it over, the signature is level.
In "Eyesight To The Blind", The Preacher (Eric Clapton) begins playing a Gibson Les Paul guitar, then switches to Clapton's favorite Fender Stratocaster, "Old Blackie".
During the climactic "Listening to You" where Tommy (Roger Daltrey) is running and crawling through water (clearly soaked), the camera shot changes to meet Tommy as he emerges over the top of the mountain, completely dry.
In the Pinball Wizard scene, The Who's John Entwistle starts playing a Gibson Flying V bass and ends playing a Gibson Thunderbird with a Fender Precision neck (a "Fender-bird"). He also begins with long sideburns but seems to finish with a fully-grown beard.
The small wooden crosses with the poppies attached to them represent the Fallen of World War One [1914 - 1918] and are not connected to World War Two [1939 - 1945], in which Tommy's father fought.
Despite a piano being heard during the Pinball Wizard scene, the local lad (Sir Elton John) is either playing random notes or not at all. The piano heard is in the background, while John is playing pinball, not the piano.
During Pinball Wizard, the display of high scores shows values in the millions and higher, but the closeups of the counter on the pinball machine show only four digits.
Towards the end, just after Tommy puts Nora and Frank's hands together, Nora's little finger moves very slightly.
During the Christmas party when Frank Hobbs whips the mask off his face, the young actor playing Tommy noticeably winces, which he shouldn't do if he were deaf, dumb, and blind.
Towards the end of Pinball Wizard, the former "Bally table king" (Sir Elton John) is being dragged out the theatre with only his boots visible; that would mean there are a dozen or more people walking over his body.
Obvious body double in the first shot of Tommy entering the junkyard. His hair is too short as he is seen from behind following the vision of himself.
During the 1945 victory celebrations, the displayed Australian flag was not used until 1954, and the US flag with 50 stars was not used until 1960.
During the Blitz (set during WW2), the first blazing wrecked car seen is a Ford Popular 100E, a model not produced until 1953.
During "There's A Doctor I've Found", Nora sings, "Let's see him tomorrow", but her lips stop moving though her voice continues.
The shadow of the camera crew is visible when Tommy is stumbling around in the junkyard.
The camera and camera operator are reflected in Tommy's pinball cane when Tommy and Nora are driving in the car.
Crew reflections are visible in pinball machines' glass during end scene in pinball park.
When Cousin Kevin is ironing Tommy after having given him the fire hose treatment, the iron is not plugged in. The power cord is actually in his hand along with the iron.
At the amusement park in the "Amazing Journey" sequence, young Tommy can be seen laughing while seated on one of the whirling rides, even though he is supposed to be completely unresponsive to his surroundings.