This is too good, he prepared himself with profesional acting just to realize one fantasy of his. He also somehow always says bullshit that goes in par with the actual story, maybe he has something similar to an unconcious mental conection with the faith, so his imagination draws information...
I think his apology was sincere, he has to be around prosecutors who don't want to help the people, who are corrupt and accept brives. Maybe he feels like he is lifting the responsability for all the prosecutors in Korea who aren't faithful.
It seems his plan is to cut the powerful conections of Jo Tae Sup by undermining the people itself, and then placing honest people to take charge, that way Jo Tae Sup will be seriously cipled in the times when he is being atacked.