Re: Just a moment... Just a moment...
I seem to recall that as Bowman removes parts of HALs CPU/Memory, he finally reveals the hidden orders about the Monolith.
This could be exposure to another flaw. HAL was programmed with a rudimentary self-preservation routine while lacking a similar routine to protect the human crew, or at least a routine which properly valued the human crew's life. I believe HAL displayed the classified video as a last ditch effort to protect system operations. It seemed like the video had been played ahead of schedule.
It all comes down to Bowman and Poole attempting to hack the system and getting bit in the ass. One should not go around a submerged submarine flicking random switches and turning random valves. Likewise one should not try to purposefully trigger a logic error in the computer running the spacecraft keeping you alive. Not to mention the programmers should have provided HAL an exit routine for whenever the subject of the secret came up. If Discussion = Mission Secret .AND. Jupiter = Still far away .THEN. "I'm sorry but that information is not relevant to current mission operations. Please do not inquire further until we reach our destination. Shall we play a game?".
It was a tragic series of human failures. And then it went off the rails with all that psychedelic alien stuff. :)