I just have two things that bug me:

1.  Why did RJ paint a smiley face on Lisbon, but not kill her.  He killed people and then drew the face.  If he did run out of time and was startled by pigeons, why not leave after she is knocked out?  For that matter, why take the chance of her coming to while drawing the smiley face?
2.  Why just out of the blue did the CBI protocol change so that Rigsby and Grace are allowed to marry?

I'm not saying that any of these people are RJ but it doesn't make sense to me.  If nothing else, it's sloppy writing.  The other thing to keep in mind:  How is The Mentalist going to move forward with these two people.  Something has to change drastically for two main characters to suddenly be off the show!