Both Alien and Aliens are so well written and so air tight, it takes some real twisting to find any loose ends on any of them. So it does come as sort of an interesting tidbit just for the curious minds to find anything in them that might not fully latch. In no way am I trying to poke or look for holes in the stories, but finding just about anything resembling an oversight in this case is simply a curiosity. Because when you ask someone to point any inconsistency and plot hole in Alien, most likely that someone won't be able to find anything. I'm not talking about stuff like the fact that the autodestruction leaves so little time for evacuation and isn't located near life boats, or Ash materializing in the room, which can be explained with little creative thinking and theorized, but stuff that is simply an oversight.
Alien is so tight because it was overseen by many intelligent and talented people, some of who were also writers such as Walter Hill and David Giler, the producers (and uncredited script doctors, but that's another debate). And also, because it's a very bare bones, simple story, not leaving much room for any errors.
There is however this one issue that is an oversight, and an overseen oversight thanks to the engaging pacing and atmosphere of the sequence. The subject at matter here is the alien getting hurt/wounded by Ripley.
In the scripts, Ripley finds a spear which she stabs the alien with and opens the hatch quickly so that the bleeding acid from its wound gets sucked out into space before touching the floor. The alien then manages to grab her ankle
In the film, she shoots it with a grappling hook and he gets stuck on it. Other than that, same ideas apply. The alien is wounded, screeches in pain and acid splashes in every direction from its wound.
Here's where the problem lies though. Both the acid that splashed out and the acid in the alien should melt the small grappling hook almost instantly but it never does. The hook even holds the alien and helps it on its way back to the hatch
One can say the vacuum of space could have affected it but the hook was in the alien. And it was shot into the alien inside the shuttle. One can also say the hook could have lodged itself in a part of the bone structure but it still doesn't explain the part that was in the alien and the acid that sprayed
The scene in Alien: Illustrated Story
Perhaps the quick change of endings created this oversight, since the scripted version with the spear contains no such thing. Usually, either the script, novelization or sometimes directors commentary explain such things, but since this wasn;t the way it was scripted, the written version of the story can;t help here. Either way, that is about the only unexplainable oversight I could think of from this great film, and it takes away nothing at all of course. Every film will have an oversight here or there. Just an interesting bit of trivia
