Factual error: Angelo claims he promised their mother on her deathbed that he would become a priest, and Sophia says she promised she would marry someone else - and we assume she died before Sophia or Angelo got married to their spouses. However, in the episode where they are flashing back for Mother's Day, Sophia's mother is in this episode along with Sal (and she looks like an older version of Dorothy).
Factual error: In the season 3 opener, Sophia befriends an elderly gentleman and spends much of the episode on a boardwalk in Miami Beach. The set design, however, replicates nothing even close to Miami Beach. Instead of chrome and neon Art Deco it looks like a northern fishing village complete with netting and buoys.