In Act III, why does the judge dismiss Giles Corey?

In Act III, Giles Corey's voice breaks through the crowd in the courtroom, as he shouts Thomas Putnam is reaching out for land. Giles asks to present his evidence before the court and is brought into the court by Herrick as Deputy Governor Danforth enters, followed by Ezekiel Cheever and Reverend Parris. Giles breaks down before the court, claiming he only wanted to know the reason for his wife's obsession with reading books and not that he accused her of witchcraft. Danforth insists Giles must present his evidence in a proper affidavit, and sends him from the court.