- Alternate Character Interpretation: Is Caine really that evil and crazy, or did his fellow scientists force his hand? Did the serum make him less empathetic and more psychotic, or did the power of invisibility simply give him freedom to be who and what he'd always been? Was it a combination of both? Actually noted in the film, "Was it the serum that fucked you up or was it the power?"
- Did Sebastian actually rape his neighbor, or "just" terrorize and molest her? A deleted scene of invisible footprints in the carpet, away from the bed where the woman is lying limp and sobbing, would confirm the former, but the final film leaves it a bit nebulous (though it's still obviously Caine's crossing of the Moral Event Horizon).
- Complete Monster: Dr. Sebastian Caine started out as the charismatic but egoistical head scientist leading a project to test an invisibility serum. After a successful run, he lies to his superiors about the project to continue with human experiments, using himself as a guinea pig to see what it was like. Initially passing the time with pranks on his colleagues, he gradually gives in to his darker inhibitions he hinted at early on, by molesting his female colleagues and eventually raping his attractive neighbor whom he constantly spied on, reasoning no one would know. Growing more unhinged and reckless, Caine batters a dog to death when he learns his ex-girlfriend and colleague Linda is now in a relationship with fellow colleague Matt. When his mentor Kramer is told about his activities, Caine murders him and decides to kill off his staff, and sets the facility to explode; leaves one member to bleed to death; manhandles one to shoot herself before breaking her neck; and locks Linda and Matt in a rapidly cooling freezer, making final attempts to kill them when they escape.
- Critical Research Failure: When Caine is injected with the serum there is visible air bubbles in the fluid. Getting air bubbles injected is at best very painful, at worst fatal.
- That could explain why Caine was in a lot of pain when he was turning invisible.
- Hilarious in Hindsight: Kevin Bacon playing a character named Sebastian. It's also pretty funny to see him and Thanos of all people were co-workers.
- Moral Event Horizon: The invisible rape sequence.
- Paranoia Fuel: One of your colleagues is invisible. And naked. And insane. And right behind you. And he wants to kill you. (Rape is not off the table, either.) Trying to electrocute him (the cure) will just turn him into a mass of walking organs.
- There's also the part of the film where Caine drags a guy into a pool and drowns him, and the guy's wife looks outside and thinks her husband just fell in.
- The transformation sequence. It's possible that even a single drop of serum is enough. Your heart just felt warm and is tingling?
- Retroactive Recognition: Greg Grunberg (the pilot in Lost, Matt Parkman in Heroes) plays a supporting character.
- Another scientist is Kim Dickens (Cassidy in Lost, Ms. Stubbs in Deadwood).
- Rhona Mitra, the vampire in Rise of the Lycans and The Gates is the rape victim. Her vamp powers would have come in handy here. Or even the combat training she got in Doomsday.
- Josh Brolin is Matt, decades before he would truly hit it big in No Country for Old Men and later as Thanos in the Marvel Cinematic Universe.
- Visual Effects of Awesome: Both the transition from/to invisibility and the invisible effects themselves are impressive. The 3D model of Kevin Bacon has since been donated for scientific research.
- What an Idiot!: As mentioned on the main page, at one point all the other main characters openly talk about their doubts and worries about Sebastian in a pretty unflattering way without making sure Sebastian isn't in the room, despite knowing that he is invisible and that he is liking using it to sneak on people. Guess where he was?
- It taking several minutes after Sebastian kills Janice for the rest of the scientists even noticing she's missing despite supposed to be right behind them.
- Surprisingly averted by Sebastian's neighbour: After hearing the doorbell ring, she looks through the door's peephole first and, seeing only an empty corridor, doesn't open. Sebastian has to ring the doorbell multiple times to get her to even open the door, and his whole ploy to sneak in only works because she has no idea that an invisible man can even exist, let alone be close to her. That makes more baffling how badly the scientists who were working on the projects and had both tools to handle an invisible specimen and a personal knowledge of Sebastian handle him.
YMMV / Hollow Man