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.
Welcome To Olesonville - S9-E3
Continuity mistake: Mrs Olsen cleans up the old Hansen house to sell, however it was made the blind school years back and burned down, killing Mary's baby and Alice Garvey.
Albert Quinn Ingalls: Ma, please don't tell me I'm too young to know how I feel.
Caroline: I wasn't going to tell you that, and don't ever raise your voice to me while you live in this house.
Trivia: Star Michael Landon was born 100 years after the real Charles Ingalls. Ingalls born 1836 and Landon born 1936. Lindsay/Sidney Greenbush (who played Carrie) was born 100 years after the real Carrie. Carrie in 1870 and the Greenbush twins in 1970.