Other mistake: There is something drastically wrong with the design of the spherical 'Aries' moon shuttle. Some seats and many fixtures are 'upside down' relative to the up-down orientation of the shuttle itself, and we see loose food trays and equipment about the place as if this is routine. But - the shuttle is designed to land on the moon. What happens then? The moon has gravity, remember? There are going to be quite a few very disgruntled people dangling upside down like spiders, and there will be loose gear (and perhaps a stewardess or two) bouncing about all over the place. It is not a matter of stowing loose gear or lying flat on landing - some parts of the shuttle are upside down relative to others, which is why the stewardess has to do that famous 180 degree upside down walk. Whichever way you look at it the shuttle is going to encounter serious problems when it reaches a gravity well, which will occur whenever the engines are fired up, never mind landing on the moon.
Trivia: Originally the film was going to end with the Starchild activating the nuclear launch platforms orbiting Earth, using the planet's destruction as a means to accelerate the evolution of mankind into its new universally intelligent form. Stanley Kubrick eventually decided against this as it was too similar to the ending of his previous film "Dr. Strangelove".
Trivia: People speculate that HAL is a reference to IBM, as the letters differ by one position. Kubrick says this is a coincidence, but was concerned about IBM's reaction to the film's references, including the IBM logo on Bowman's spacesuit. However IBM had no problem as long as they weren't associated with the "equipment failure," or listed as technical advisors for the computer.