@TD
I'm actually not that good in picking out flaws in films - certainly not the first time I watch them. Every time I watch a film for the first time I put on the English subtitles, even though I'm a native English speaker. I'm not deaf but I'd describe myself as a lazy listener - if a scene is visually interesting, I'll not hear what's being said.
In all the examples I've given in this thread, I've seen the films many many times.
Here's a little error in Fright Night (1985) which should've been fixed in the edit: when Jerry Dandridge is behind Charley and says "now we wouldn't want to wake your mother, would we Charley ... then I'd have to kill her too" if you look carefully, you'll notice that when the camera switches onto Charley's face at the end of each line, Dandridge's mouth is mouthing his line (@3mins 26secs).
https://www.youtube.com/watch?v=umXsFrL6kcA
Yeah, I've seen Fright Night many times, too, lol.