As the crowd is running out of the movie theater the same man in a light, checkered short sleeved shirt wearing sunglasses runs out three times.
Just before Steve and Jane attempt to hide in the freezer, Steve grabs a black steel pole leaning on the wall and hurls it at the Blob; when they come out again, the pole is back where it was originally.
In the film's third act, Lt Dave's shirt alternates between having one or two buttons undone in various shots.
Jane's dress changes from pink to yellow. Her dress is yellow from the first scene.
When Mr. Andrews walks into the police station his jacket is cross-buttoned but when the camera pans back to him the jacket is neat and tidy.
Keith Almoney, who plays Jane's little brother Danny, had his name misspelled in the credits as "Kieth Almoney."
Veteran actor Olin Howland is listed in the credits as "Olin Howlin," playing the role of "Old Man."
They're shut up in a meat locker, the cold of which repels the Blob, but although they're breathing heavily, no vapor is seen.
Jane claims she didn't exactly see The Blob, yet she saw it on the old man's hand.
However, she did not witness Doctor Hallen being consumed by the fully-grown Blob, therefore she could not corroborate Steve's account. That is why she contritely said "Not exactly."
However, she did not witness Doctor Hallen being consumed by the fully-grown Blob, therefore she could not corroborate Steve's account. That is why she contritely said "Not exactly."
When the old man touches the meteor with the stick, you can see the cracks before it opens up. These may be a result of the meteor's impact.
When Steve and Jane sneak out of the house and are talking in the driveway, smoke can be seen rising behind Steve in the lower right hand corner. This is smoke from a lit cigarette that he is holding behind his back. Steve McQueen smoked on set and refused to put the cigarette down.
When a shot from outside the diner shows The Blob climbing onto it, the diner is clearly only a photograph, as The Blob makes a clear shadow on the diner, the sky, and the street.
When Steve and Jane stop to help the old man on the road, The Blob is covering the old man's right hand. The Blob is supposed to absorb flesh on contact. However, the old man clearly touches The Blob with his left hand, and that hand is not affected.
During the backwards drag race, the car exhaust can be seen going back into the exhaust pipes.
Steve is supposed to be a young guy/teenager, yet his wedding ring is clearly visible toward the end of the movie.
At 1:05:01, as the actor awakens and dons clothes, the siren (added in post-production) changes from air raid to fire. The Director can plainly be heard off screen cuing the actor with "Fire" just before the actor says it.
A crew member can be seen in front of the box office of the movie theater when the audience is fleeing The Blob.
Shadow of the boom mike on the cop's face after they break into the locked room at the doctor's house.
In the Dr's office when the police sergeant is leaving to break into another room from outside, the large light he was using because there was no power in the office had a power cord that he dragged with him as he left.
At time 7:13, Steve gives up on finding the meteor landing spot. He starts the car, and begins to drive back to town. An inexplicable cable is clearly visible trailing behind the left side of the car, maybe a microphone or lighting cable.
The Blob can't stand cold, yet it crawls through the running air conditioner blowing cold air.
After The Blob is stopped, everyone escapes the diner through the basement window instead of going back upstairs and exiting through the doors.
As the theater audience flees The Blob, many of the extras can be seen laughing and smiling.
Steve doesn't have his headlights on, and it's night time.