Red John's Friends episode

MinelliI: Wake up, Dorothy. You're not in Kansas anymore
Jane: If I'm Dorothy, then who are you?
Minelli: It doesn't matter who I am

At the end of episode appears the famous HE IS MAR...
In "The Wizard of Oz" one of the characters is the Professor MARvel (captivating but false soothsayer).
I Think the message on the wall is an answer to the question of Jane.