Watch the bum's fingers in City on The Edge of Forever (actor John Harmon). He's missing the fourth finger on his right hand. But when we go in for the close up as he's playing with the phaser (just before he zaps himself out of existence), his hands magically show a full 10 digits.
Amok Time: Among the most severe glitches in this episode occurs in Spocks quarters as Kirk says "I haven't heard a word you've said" as the statue in Spock's bedroom in the background flames out -- the gel in the light has melted and there's a huge plume of smoke coming out of it.
You will recall, "Robert April" was one of the suggested names for the Captain of the Enterprise when TOS was first developed. Roddenberry also used the name Robert April for a character in a Have Gun Will Travel episode he wrote, season 2 ep 32, chaplain Robert April, of whom Paladin said "I respect him more than any man I ever met”.
~ Mister Atoz