Mr. Tong had previously refused to confess, not because he had an unyielding will, but because he had signed a Secrecy Pact with others. Once he revealed the secret, he would be killed by the curse attached to the pact.
That's how the wealthy businessman had died before.
After the curse was lifted, he spilled the beans like bamboo tubes spilling beans, confessing everything he knew… at least all the information about the Holy Grail Church, completely and thoroughly.
The current Holy Grail Church is not the same organization as the one in the past.
The past Holy Grail Church was described in the autobiography of the Emperor of Heaven, laden with countless sins, too numerous to document. The intent of that sect back then was to study "God's Blood" and summon Ancient Gods from the Holy Grail.