Based on these lines, what role did friar john play in the catastrophe

Based on the given lines above from Friar Laurence’s dialogue from Act V, scene iii of Romeo and Juliet, the role that Friar John played in the catastrophe is that, he made the choice not to deliver Friar Laurence’s letter. Hope this answer helps. 

Iwould need the poem to you answer that

Ceuphemism hope it