Sorry for my english

Regarding the involvement of Lisbon in the prom episode, i shall share my theory i did 6 episodes ago :

I DON'T say that Teresa is red john but this theory is made in order to reveal the importance of Teresa in the plot.

Background:
- Teresa is playing poker with Bertram, and some other big names of justice, police etc..in some previous episodes
- Teresa Lisbon has been kidnapped but not killed (spared) by Red John who left his bloody smiley on her face.
- The nurse when Lisbon is in the hospital comes up with saying: Are you Carmen Lee ? Something like that.
- One of the episodes is entitled : The green thumb = > The Green Thumb

Implications and conclusions :

I think Teresa Lisbon return to the center of the plot with respect to the following:
First name Teresa means Harvest
The name given by the journalist Carmen means Garden
One of the episodes that follows is called The green thumb

The name Carmen came from a patron saint of the order of caramel whose main reform was introduced by Teresa D' alvila .
This Teresa alvila lost his mother at age 12 as Teresa Lisbon " In 1527 , at the age of twelve, Theresa lost her mother. "
When Teresa died  her body was separated , and her left hand was sent to Lisbon.

The Carmelite Order has seen in it 5 Theresa beatified , the first we have seen with previous reconciliations.
Other
links  can be done including the title of the episode 1 where it is
believed that Teresa is dead "The Desert Rose" which ic a toxic rose
with 5 leafs . In fact there is another character of the same religious
order: Therese of Lisieux who died the day the episode comes out on
September 29 and whose religious attributes are a cross surrounded by
roses.

For the third Therese , She is Marguerite Therese of the
Sacred Heart , the link with Lisbon is due to the fact that the body of
this one  was disfigured by the disease but became totally healthy and
lifelike after death. It reminds us of the " renaissance/rebirth" of
Lisbon who was believed dead after being disfigured by Red John .
Moreover her real name is Anna that brings us to the name of Annabeth
the  niece of Lisbon .

For the fourth, she is Thèrese Andes here again we find the attribute of roses, with her learning of the rosary.

The
last is  Teresa Benedicta of the Cross,, his main research led her to
believe that union with God through suffering considered as " fire
atonement " as Jesus Christ in his suffering in the Garden of Gethsemane
==> Several elements to clarify here:
The
term union refers to the work of a certain John of the Cross who speaks
about Mystic Marriage in his book "Dark night" where the soul rises to
God , which enlightens the title of episodes black winged redbird and
Wedding in red . Besides two previous Teresa experienced this mystical
marriage.
Moreover " fire atonement " refers to the rest of the poem Tiger " Tiger Tiger fire and flame ! "

Those are the information that brings us the first name Carmen pronounced purposely by the nurse. What about the name Lee ?
It
is cleared by the latest information about Garden of Gethsemane . If we
reverse the letter's order of Lee we obtain Eel. the Eel River is a
river situated in Sacramento (where the show takes place).

It
was in the Garden of Gethsemane that Jesus and his disciples were
arrested . This reference is almost exclusively in the Gospel of John. I
recall here the name Carmen means Garden as I said at the beginning .


I
conclude : Teresa is the garden where Red John is stopped ( like Jesus
in the garden of Gethsemane ) . Teresa is the one holding  the final key
to the mystery.
The tiger is the ideal and the perfect organization
that Red John dreams about, imposing and well shaped ( as shown in the
poem ) .

Hence my personal conviction is that she will have to 
betray Red John because she is an accomplice. why else Brett would have
whisper to her : Tiger Tiger considering the fact that in the last
episode we know that this is a sign of recognition between accomplices 
of Red John.
Pass through the fire of the atonement which is a test of suffering (

see above)  means going beyond this obstacle whatsoever it costs to

Teresa (for example if she is an accomplice of john, the betrayal)