I would guess that disobedience in any religious organization would considered a biggie thingy.
Did you read in the article that the offending priest was sexually molesting male youth in the confessional? Just imagining that makes me ill to my stomach.
The whole centuries-old scandal, entombed within the very heart of Rome, is nauseating, not the least of which includes RC apologists who deny the abuse took place, call the victims names and perpetuate the abuse by their own ignorance and/or callous disregard for the truth.