Corrected entry: When the film starts you see the bridge and a stack of papers flap in a breeze.The crew are in hyper sleep and don't need oxygen so it's very unlikely they would have their valuable oxygen supply switched on and turned up enough to make a breeze for the 20 months it takes to travel back to earth.
Corrected entry: Ripley has just seen Lambert and Parker dead, she has set the ship to destruct, so why does she go to the lower deck? The only reason is to show us, the viewers, Dallas and Brett still alive and cocooned and to show us the sticky secretion on the wall, which we see more of in "Aliens."
Corrected entry: When the crew split into two teams of three, Ash gives Ripley a movement sensor, which he tells her detects movement in the direction its pointing. However, when Ripley points the sensor at Brett and Parker (who are both moving at the time) it doesn't detect their movement. (01:00:35)
Corrected entry: Take a close look at the masks they are using when they remove the helmet from Kane. The masks they are using to prevent contamination are nothing more than ordinary oxygen masks that one uses at a hospital. This is evident by the hose receptor on the bottom of the masks. In reality these masks would not prevent them from catching any airborne disease that this alien would have. I know they are in a infirmary, but a space ship would/should be better equipped in case it comes in contact with other life forms. (00:36:40)
Corrected entry: Looking back, it's kind of absurd that the Alien wasn't discovered hosting in Kane's body prior to its bursting out of its chest. The facehugger was enveloping his face for quite some time and the medical equipment aboard the ship determined that it was shoving something down his throat. Once it falls off of him, the rest of the crew didn't conduct a thorough examination of him to make sure he's fine before sitting down with him to dinner?
Corrected entry: When the face sucker jumps at Kane, he only jumps onto Kane's helmet. This is best seen when in slo-mo on the DVD. Having it jump through his helmet, as we are led to believe, would have resulted in some glass breaking and facial lacerations to Kane and injury to the face sucker alien. (00:34:20)
Corrected entry: Technically speaking, it is impossible to detect the Alien by micro-changes in air density. This is because the device would constantly be reading the mass(i.e. density) of the air molecules around it, and any movement would set it off, as the air molecules would be moving. Even breathing would set the device off.
Corrected entry: The director's cut of the movie contains a continuity gap with James Cameron's Aliens. In the sequel, we learn that the eggs containing the facehuggers are laid by an Alien Queen, who is protected by drones and warriors. However, in the director's cut version of Alien, we see that the captured Brett and Dallas being slowly transformed into eggs when Ripley comes upon them as she races for the shuttle. (Even in the theatrical version of Alien, we don't actually see either Brett or Dallas being killed; we just assume they have been when the Alien grabs them.) When asked about this later, James Cameron replied that since the released film version of Alien omitted these scenes, he did not consider them canon and did not feel bound by them.
Corrected entry: The alien is growing much faster than it devours victims, at times even becoming maybe ten times bigger without killing at all.
Corrected entry: After Kane has volunteered to be in the first group to go out, Dallas says "you too Lambert". After she replies "swell" Dallas says "I'll break out the weapons" - where are the weapons that Dallas is referring to? Why could these not have been used to arm the crew, when the Alien was loose on the ship instead of trying to hunt for it in the air shafts with a solitary flame thrower?
Corrected entry: When the crew goes into the ship with the eggs in it, you can clearly see that all their gloves are hockey gloves just painted over. Pretty cheap. (00:29:35)
Corrected entry: In the scene where Ripley is leaving in the escape ship, she's looking out the front window looking back at the ship as she's leaving. When she was prepping the escape ship moments before, the cockpit window is facing outward. If the ship took off nose-forward, she could not see the mother ship moving away through the front window as then she'd be going backwards. There is a small window in the back of the ship through the rear door, but it's far too small to be the same window she was looking out while leaving. Also, the front window has diagonal support struts to hold the windows in place, providing further evidence that the window she is looking through is actually the front of the ship.
Corrected entry: It's difficult to see, but the instructions for self destruct (at least those for cancellation) appear to be in French. (Although fleeting, this is easier to spot in the cinema than on DVD) (01:34:25)
Corrected entry: At the beginning of the film when they come out of their hibernation chambers, they all get up and are walking fine and a couple of characters are clean shaven. Surly if they were in the hibernation thing for many years they would have grown excessively large beards and also would have been very unstable when walking. Just like in real life where astronauts find it difficult to walk on their return to earth.
Corrected entry: In the scene directly after Brett is killed by the alien, when they cut to the crew discussing it Parker seems to discuss the alien like he has seen it but I am not aware of any scene where Parker sees the alien. He makes numerous comments about how huge the creature is. How did they even know that Brett is dead let alone the size of the creature? (01:08:10)