Why don't you add yours to the other 44 mistakes in Alien at Movie Mistakes?
It is Sci Fi, it doesn't need to make sense.
Just watch it for what it is.
I'm going to try my best to not sound arrogant here.
I study Film and TV and am currently in my final year, I read about and watch a lot of films, to say I know more than you about the subject? No not necessarily, but I'd like to think I'm not ignorant on the topic.
Anyway, there is a person on the crew hired SPECIFICALLY for continuity, the idea being that when the film is in post-production it should make sense when it is cut together. If it doesn't matter tell me why this person is hired?
Secondly, it's not about it
making sense, it's about production values. Something as simple as drinking a cup of coffee really does have to make sense because it has no relation to the narrative, Ripley is simply drinking a cup of coffee. This cup of coffee has no agenda....
Furthermore, it just makes the production look tacky. As I say, narrative structure doesn't have make 'sense', Magnolia is proof of that. But something as simple as drinking coffee in the same scene.....yes it does.
When I see a mistake as obvious as this it reminds me that I'm watching '
just a movie'.