Revealing mistake: When Rocky climbs the RKO tower, he carries lifeless Frank-N-Furter on his back. In the wideshots facing the stunt doubles' backs, while Rocky has both of his hands on the tower, the very much dead Frank-N-Furter has his right arm firmly around Rocky's neck to hang on.
Revealing mistake: Just minutes after Rocky's creation, when he is lifted out of the tank, there is a nice close-up of Rocky's face. The newly created man with the "Charles Atlas seal of approval" has a few silver fillings in his upper right teeth, which are easily visible as he sings, "Over my head and I've got the feeling..."
Revealing mistake: When Rocky lifts Frank-N-Furter's body Rocky is barefoot, wearing only the stockings. When Rocky is climbing the RKO tower, carrying his creator, evidently Rocky is wearing a type of thin shoes under his stockings. The stunt double did this as a safety precaution. (01:30:35)
Revealing mistake: The saxophone Eddie plays in "Hot Patootie" has no reed. (00:43:10)
Revealing mistake: When Dr. Scott's wheelchair is being pulled by Frank-N-Furter's magnet, just after passing Magenta and Columbia, Dr. Scott soars up the next flight of stairs. Look between the cobwebby banister bars and you'll notice that the 'stairs' are actually a flat surface. (01:01:20)
Revealing mistake: When Rocky first stands up in the tank still bandaged, he doesn't get up directly underneath the colour machine, which he is going to grab onto moments later, because he can't see; you can see him trying to shuffle discreetly into the right position.
Revealing mistake: After Frank-N-Furter pulls the lever to immobilize Janet, Brad and Dr. Scott, Janet's feet are positioned close together when Frank-N-Furter shouts, "Planet Schmanet Janet,", but when she screams, "Stop!" her supposedly immovable feet now have a space of about 2 ft. between them. (01:10:50)
Revealing mistake: In the laboratory, when the tank is unveiled, fishing lines are visible strung across the top of the tank (probably to keep the red sheet from dipping down into the water). Watch closely in the reverse shot after Magenta and Columbia throw off the sheet. (00:33:45)
Revealing mistake: At the end of the movie when the castle shoots into space, if you look just as it gets really misty, in the background (it's maybe just centimetres off) you can see the real castle. The one that blasts off is a cutout. (01:34:10)
Revealing mistake: At the end of "Hot Patootie," an enraged Frank-N-Furter snatches an ice axe from the deep-freezer and menaces the terrified Eddie. There is no blood seen in the freezer at this point. Frank swings his first blow and completely misses Eddie, who is scampering into the deep-freeze several feet ahead of Frank. There is no blood seen in the freezer at this point, either. Frank then pursues Eddie into the fog at the back of the deep-freezer and viciously murders him with the ice axe (a genuinely horrifying scene as Tim Curry plays it, but the murder occurs entirely off-camera). But then, as Frank emerges from the freezer moments later, we see a splattered and gory trail of fresh blood leading into the freezer, as though Frank had already mortally wounded the escaping Eddie even before the offscreen murder. This looks as though footage from an alternate and more graphically violent version of this scene was kept in the revised scene, causing the gory blood trail to appear out of nowhere. (00:45:15)