Old Friends - S3-E1
Other mistake: Blanche asks Daisy to go to Rose's room to get the things she set out for the rummage sale. Daisy goes into the first room on the right and gets the items, including Rose's teddy bear. Blanche gives it to her for helping out. Rose comes home, goes to her room and comes back asking where her bear is. Problem is, Rose's room is at the end of the hall on the left.
Other mistake: In the 1954 flashback scene, it is Dorothy's 10-year anniversary, so she got married in 1944. In another episode, Dorothy said Stan impregnated her in the back seat of a car by saying he's going to the Korean War, which began in 1950. Also, viewers know that Dorothy went to college. A pregnant newlywed in 1944 with a husband off to war would not have gone to college but stayed home awaiting the birth of her child. And in 1945, after the war, she would have been a housewife, not a college student.
Suggested correction: First off, I don't remember the show every showing or saying Stan did serve in the military. Dorothy said the only reason she went out with him was because he claimed he was being shipped off to Korea and would probably die. Stan was shown not to be faithful and probably not very trustworthy. But there's no reason an intelligent woman with a child could go to college even if her husband was in the military.
Other mistake: Towards the end of the episode, Stan gives Dorothy a box with the ring in it she pawned earlier. But she says "my ring!" before even opening it - she had no clue it was that same ring rather than a different one.
My Brother, My Father - S3-E17
Other mistake: It's raining outside. Dorothy comes in the house and says "it's really coming down", then shakes her coat off although it's not wet. Then Stan shows up with an umbrella that's not wet. Then Sophia's brother Angelo shows up and isn't wet either. (03:20:50 - 03:22:45)