What are some quotes to prove that Friar Lawrence is to blame for the deaths of Romeo and Juliet?

Friar Lawrence plays a significant role in Romeo and Juliet's fate and is responsible not only for secretly marrying the two lovers but also for concocting the flawed plan that leads to a drastic misunderstanding on Romeo's part when he arrives at Juliet’s tomb. In act 2, scene 3, Romeo visits Friar Lawrence and explains to him that he is now in love with Juliet. Friar Lawrence is initially astonished, but he agrees to secretly marry the two lovers, saying,

But come, young waverer, come, go with me, In one respect I’ll thy assistant be, For this alliance may so happy proveTo turn your households' rancor to pure love. (2.3.89–91)

In act 4, scene 1, Juliet arrives at Friar Lawrence's cell and explains to him her desperate situation. Friar Lawrence proceeds to create a plan, which involves Juliet drinking a sleeping potion that will make it seem like she is dead. Friar Lawrence gives Juliet the vial and tells her,

Let not the Nurse lie with thee in thy chamber. [shows her a vial] Take thou this vial, being then in bed, And this distillèd liquor drink thou off,When presently through all thy veins shall runA cold and drowsy humor, for no pulseShall keep his native progress, but surcease.No warmth, no breath shall testify thou livest.The roses in thy lips and cheeks shall fadeTo paly ashes, thy eyes' windows fallLike death when he shuts up the day of life. (4.1.94–104)

Friar Lawrence then proceeds to explain that he will send a letter to Romeo in Mantua describing the plan, and Romeo will rescue Juliet from her tomb. In act 5, scene 2, Friar John explains to Friar Lawrence that he was unable to deliver the letter to Romeo, which prompts Friar Lawrence to say,

Unhappy fortune! By my brotherhood,The letter was not nice but full of charge, dear import, and the neglecting itMay do much danger. Friar John, go hence. Get me an iron crow and bring it straight Unto my cell. (5.2.17–23)

Tragically, Romeo discovers Juliet, believes that she is dead, and commits suicide beside her tomb. When Juliet awakens from her sleep, she discovers that Romeo is dead and also commits suicide. When the royal families arrive at the scene, Friar Lawrence takes responsibility for Romeo and Juliet's deaths by saying,

I am the greatest, able to do least,Yet most suspected, as the time and placeDoth make against me, of this direful murder.And here I stand, both to impeach and purge,Myself condemnèd and myself excused. (5.3.238–243)

Friar Lawrence then proceeds to explain how he secretly married Romeo and Juliet and describes how his plans to reunite the two lovers went awry.

I believe that Act 2, Scene 3, is a good place to start for finding quotes that would help support the idea that the friar is to blame for the deaths of Romeo and Juliet. This scene has the friar agreeing to help Romeo and Juliet be together.

But come, young waverer, come, go with me.In one respect I'll thy assistant be,For this alliance may so happy proveTo turn your households' rancor to pure love.

The friar isn't completely convinced that Romeo is in true love with Juliet; however, the friar sees the relationship as a possible tool that can be used to help mend the Capulet and Montague feud. It's possible that if the friar had discouraged the entire thing, Romeo and Juliet would not have wound up dead.
I think the quote that has the strongest evidence against the friar can be found in Act 4, Scene 1. Juliet has gone to the friar to weep and be consoled. She speaks of killing herself, and the friar rightly tries to talk her out of doing that; however, his suggestion is for Juliet to just appear dead:

If, rather than to marry County Paris,
Thou hast the strength of will to slay thyself,
Then is it likely thou wilt undertake
A thing like death to chide away this shame,
That copest with death himself to ’scape from it.
An if thou darest, I’ll give thee remedy.

He gives her a potion that will make her appear to be dead for 42 hours. The friar will then send word to Romeo about the plan, and Romeo and Juliet can escape together forever. The plan appears to be a workable solution. A problem is that Romeo never gets the message, and more deaths follow as a result. I can't entirely blame the friar because he didn't force Juliet to take the potion, but I do believe that events would have occurred very differently had the friar never brought up the faking death option.