A pretty good reason why the episode was fake:

The Red John saga should have been over by now, the Red John episode was supposed to be launched 17 nov. Then it got postponed. We don't know why. I think the whole fake episode idea is something the producers came up with last minute. Something to make the episode different. To be remembered.

I hope that I am right, otherwise the finale is just a huge disappointment.

Just a guess

They should have made a movie instead without Heller's input. We all thought he was genius but anyone can throw in red herrings with no real plan in the end or smart conclusion or twists.

I agree this is one of the funniest sites. www.red-john.info -The comments are hilarious.Someone should add the one about the T-shirt that ANOTHER poster left a few comments down
" I followed Red John for 5 years and all I got was a pigeon!

Priceless guys.

What are we gonna do when we find out that this was the real episode. I have to wait up until 3 o clock to watch it and it could be the same one. I don't care if they explain stuff in the next episode..that's not good enough. He had Red John there with him. There could have been a amazing showdown. Something spectacular. It was not good enough.

No offence but the show is ruined for me if this was it. I won't be tuning in anymore. There would be no point. It would just be silly. Also why didnt they wait until Red John was dealth with before introducing the new characters. The very end of the episode could have been them packing everything up.

I can't make sense of this.

So I guess all the piegeon theories were correct. There were little pigeon clues in every episode

PS.
Someone said there should be a pigeon t-shirt, so I made it, check it out! 
http://teespring.com/PIGEON