As Long As We're Together (2) - S5-E2
Revealing mistake: When Charles Ingalls plays his fiddle at the end of the episode, one can see from the movement of his hands that he is not really playing, but just pretending. (Also visible in every other episode where Charles plays the fiddle, but most obvious in this one.).
Continuity mistake: During the final football game, the sun position changes from one side of the field (before the game starts) to the other side during most of the game then back to the first side for the last play of the game.
There's No Place Like Home (2) - S5-E6
Other mistake: At the very end, Mr. Hanson is seen walking toward the church. Because of his stroke, he's slow and unsteady. We see several close-ups of his feet, showing how he's struggling. Two of those shots are the same footage. It's obvious, because you see that he drags his foot over a small stick in the road and stumbles - and in both shots, it is exactly the same.
There's No Place Like Home (2) - S5-E6
Continuity mistake: At the end, when Lars Hanson hears the church bell ringing, he gets up from his bed and goes to look out the window. When he first gets up, his hair is completely tousled - definite "bed head." The shot changes to show him leaning out the window, and his hair is neatly combed. When the shot returns to the inside of the room, his hair is once again rumpled and untidy.
Visible crew/equipment: When Michael Landon is chasing the boy at the carnival, the shadows of the crew can be seen on the bottom of the frame as he is running.
Character mistake: When Eric is asked to spell repetitious at the spelling bee he spells it R E P I T I T I O U S... Alice Garvey says "correct" but it was incorrectly spelled.
Someone Please Love Me - S5-E22
Continuity mistake: Charles walks down the staircase with a small trunk, suitcase, and a duffel bag. He finishes business from the man he bought the horses. When he walks out onto the porch, Charles is only carrying his duffel bag, and tosses it into his wagon. No other luggage is visible.