Of all the men and women present at the wedding, only Friar Francis actually "notes" Hero. He says, "By noting of the lady...trust not my age...If this sweet lady lie not guiltless here" (4.1.157,166,168). The Friar is correct as we all know, and his choice of words, "by noting of the lady" is significant. It is the first time that anyone points out to the characters what we all know to be true; they fail to note what is happing around them.
Friar Francis is similar to Friar Laurence in Romeo and Juliet. He tries to save Hero by making her seem dead. "Come, lady, die to live" (4.1.253). This parallels the death of Juliet. The later marriage between Hero and Claudio will serve as a resurrection moment. Thus Friar Francis plays God with Hero's life and later resurrects her in a shroud of death.