Just a kind of Prediction.
in the next episode "Red Listed" if Robert Kirkland won't be dead , I think he will do something to make him out of the List of 7 suspects ( Like i've seen in some theories, the idea of going to jail for example, or doing something else ) , and when jane will analyze 5 remaining persons behaviors ,won't find out someone who fits and then The Real Red John will be revealed.
I can't imagine Robert Kirkland not being Red John , he is well-organized and know exactly what he is doing.
