Will King at 2015-07-04 21:48:10:
Capricorn One (1977)
Writer: Peter Hyams
https://www.youtube.com/watch?v=cI4qYsP9oME
WILLIS: There's this guy, see. He takes a trip to Europe. It's his first vacation in a long time. He sees the sights, you know. He has a real good time. Anyway, after a while he decides to call home. He gets his brother on the phone, and the guy says to his brother, how's everything at home? And his brother says, your cat died. And the guy says to his brother, You shouldn't tell me bad news like that. You should break it more gently. You know, like, you should say something---the cat crawled out on the roof, and chasing the squirrels, and got stuck. We had to call the fire department. And when they finally got there, the fireman crawled up, he grabbed the cat, but on the way down he slipped and the cat fell to the ground. And they had to take the cat to the vet. They tried to save the cat. They had to operate on the cat, but it was too late. They couldn't save the cat. That's how you should break bad news like that. So, the guy says to his brother, how's Mom? And the brother says, she's on the roof. Get it? She's on the roof. (He begins laughing.) She's on the roof, get it?
(Some distance away, Caulfield sees the signal flare from Willis.)
DIALOGUE ON DIALOGUE: After a staged mission to Mars goes awry, three astronauts escape from a abandoned military base and try to return to civilization to expose the corruption at NASA, knowing that to be caught means certain death. Each goes in a different direction. The direction taken by Peter Willis (Sam Waterston) forces him to scale a sheer cliff. Willis tells himself the joke story about the death of the pet cat to try to keep himself sane as he climbs. At several points, the story of what happened to the cat parallels the dangers Willis faces ("He sees the sights"---Willis' journey through the desert; "He has a real good time"---Willis is terrified during the climb; "he slipped and the cat fell to the ground"---just as Willis struggles to save himself from falling). As he reaches the top and tells the punchline, he finds himself confronted by two of NASA's chase copters awaiting him "on the roof." He fires the signal flare to announce to the others that he's been caught.
[NOTE: The uploader used software that put an overlay on the first 60 seconds of the scene. Unfortunately, I couldn't find any other copies.]