When C.D. is sniffing out the fire at the end, he walks to the firehouse, arms down. From the front, his arms are up, from the back, arms down, front arms up, back arms down
As CD is sitting down to write a letter to Roxanne in his dressing-gown with a bird on his nose, about 1:21:26 into the film, the close-up shot shows the Cyrano De Bererac statuette facing towards him. In the subsequent wide-shot, it's facing away from him.
In explaining quarks to C.D., Roxanne (an Astrophysics PhD student who should know better) mentions that there are six types of quarks and that the "top" and "bottom" are the most common kinds. She meant "up" and "down" (which form protons and neutrons). Experimental evidence for the predicted "top" quark was not announced until 1995, 8 years after the film's writing.
C.D. reverses the sequence for getting water to the fire, specifically the hose diameters from the hydrant to the pump, and the pump to the fire
When looking through the telescope, a bright red nebula is visible in the field of view. In fact, nebula, when seen through even the biggest telescopes, appear as a gray smudge to the human eye.
When they're carrying the telescope it's what is known as a German Equatorial Mount. I requires the tube to be in a 'saddle' so the tube can be rotated. The 10" tube is bolted to the mount.
The 2015 Mill Creek DVD does not have English subtitles.
As the barn door is open to put out the fire, the "fire bar" (steel bar with gas jets) is visible.
There is an establishing shot of a cat up a tree with the camera high up in the tree looking down. The cat is obviously fake and on the wide screen version we see a crew member's hand come in from the lower left to steady the fake cat. We know it's not the fireman's hand because he hasn't gone up the ladder yet.
(at around 1hr 3 mins) Crew are reflected in the door window-panels during the first letter writing session at CD's house.
When Charlie asks how many insults about his own nose he's delivered in the bar someone yells, "14, Chief!" when in actuality it was 18 or 19. (One was deleted in the TV version, resulting in the different totals.)
Bales actually thinks of 25 jokes.
When Roxanne is hiding outside the firehouse, and C.D. offers her a blanket, she says "No - I'm fine standing naked out here in the cold", she later says that she was being ironic. Except she wasn't, she was being sarcastic.
When Roxanne is forced to walk naked back to her house after C.D. fails to get her a blanket, Roxanne asks why and C.D. explains that she said she didn't want one when she said she would rather stand out there in the freezing cold. Roxanne replies that she was just being "ironic," when she was in fact being sarcastic.