Visible crew/equipment: In the beginning of the movie (about 10 mins. in) Steve McQueen and Aneta Corsaut are driving along and think they hit an old man on the road. They stop the car and get out. There is a shot of the rear right panel of the car, two sets of "lights" are visible reflecting off the car. One single light and 4 lights in a square shape to the right of it. They help the man into their car and there is another side shot of the car and the lights are now 3 sets of 2 lights. They're in the middle of nowhere, at night, along a country road. It looks like "light trees" used to illuminate a scene at night.
The Blob (1958)
1 visible crew/equipment mistake
Directed by: Irvin S. Yeaworth Jr., Russell S. Doughten Jr.
Starring: Steve McQueen, Aneta Corsaut, Earl Rowe, Olin Howland
Other mistake: At or just after the point where Steve McQueen restrains the diner owner from running out the door - McQueen's wedding ring is visible on his left hand throughout one entire long-shot. (He was 27, despite playing a teenager, and had been married to Neile Adams for more than a year).
Steve Andrews: How do you get people to protect themselves from something they don't believe in?
Question: The movie was made in 1958, why does the calendar in police station show July 1957?
Answer: Because movies aren't always set in the year they're released. Absent any conflicting information, the assumption must be that the events of the movie take place around July 1957.