Revealing mistake: Watch closely the two scenes involving the Robot; (1) When the Omega 17 IDAK battles with the Robot you will see pieces of his plastic collar continually. (2) After Verda and the Alpha IDAK disappear you will notice the Robot's lower shutter falls out.
Character mistake: Dr Smith who has some of The Robot (ie, bravery and courage) quotes The Fall of The Light Brigade but mistakenly says "into the valley death rode the five hundred" when it is actually 600. Both Dr Smith and the Robot would know this very famous poem's most well known line. (00:44:45)