Audio problem: When Nada first sees the police helicopter, the only sound is a very muted whooshing of the blades. Any other time, the noises are normal.
They Live (1988)
1 audio problem - chronological order
Directed by: John Carpenter
Starring: Keith David, Meg Foster, George 'Buck' Flower, Roddy Piper
Revealing mistake: During the big fight scene, you can tell easily that Frank is wearing knee pads (try looking when his pant leg is wet). Construction workers will often wear knee pads for work but most often they wear them on the outside of the pants to save the knees of their pants. (00:58:50)
Trivia: The big fight scene is spoofed in "South Park" when the crippled kids Timmy and Jimmy fight, instead of the film's Nada and Frank. The episode is called "Cripple Fight".
Question: Why did all the police officers destroy the shantytown? And why did they beat the blind priest to death?
Answer: As part of the alien takeover, they're suppressing any resistance and discussion of the plot. They know there's a group, led by the preacher, who are onto the conspiracy and that they're somewhere in the camp. They destroy the camp to disburse them and prevent word from getting out.