Other mistake: At the end of the movie Lorraine has to remind Elise that she helped her once, implying they haven't seen, or spoken since. When Elise first meets Josh in the 1st insidious she tells Josh that her and Lorraine have been friends for a long time, implying they talk or see each other regularly.
Suggested correction: That's debatable as the word "friend" does have to do with semantics. I have friends I have not spoken to in a long time, or speak with rarely, but still consider them friends due to our history. Others would say that's not a friend as that's not what they think of when they hear the word "friend." So it does depend on the individual person. It's also quite possible this is what they told Josh as the cover story for why she was contacted since they initially didn't want him to remember his past.