Continuity mistake: When "Lefty" is at the car crash site, you see a blue mobile home going down the road, but it is not there in the next shot. (You may not be able to see this in the full screen version (4:3)).
Continuity mistake: At the radio station, Leatherface cuts into the tube with the beer cans on ice. In slow motion, the chain comes off the chainsaw. After the cut, the chain is back on.
Continuity mistake: The tape recording of the killings Stretch has is in her right hand. A shot later, it's suddenly in her left hand with her purse in her right hand. (00:16:18)
Answer: It's basically Leatherface's version of an orgasm. Stretch appeals to his sexuality in order to survive, and he's aroused. He uses his chainsaw as a phallic object, rubbing it against her leg and then pressing it into her groin, and is panting, which obviously symbolizes his idea of sex. And then he becomes aggressive, revs up his chainsaw, and destroys the studio in an explosive emotional display, not unlike the strong physical/emotional sensation that comes with an orgasm. You could also theoretically make an argument that the mess he creates by sawing and throwing things around specifically represents male ejaculation, which involves a pulsating release of semen and can be, let's just say, "messy" sometimes depending on what sexual activity you're doing.
TedStixon
Thank you.
Rob245