Don’t misunderstand, I think there’s a (
very fuzzy) line to be drawn. I simply can’t abide the notion that, in the context of a passage obviously intended to
empower people to act to correct the liturgy, the Pope actually created a massive new category of sin: failure to report a liturgical abuse and pursue such complaints to the highest level possible. And that instead of saying that plainly, he worded it obliquely, with absolutely no citation or reference to the Church Fathers, canon law, theology, or anything else.
I am inclined to agree that in some cases it would be sinful to fail to bring certain types of abuses to light – especially if one kept silence for the
purpose of allowing them to continue – but I think such an argument would have to be propounded on a case-by-case basis with due regard to the circumstances, and that one cannot simply say, “It is a sin if you don’t report an abuse. See RS.” RS, after all, doesn’t say we should exercise extra diligence to stamp out graviora delicta. It says that a person must do “all that is in their power” to eradicate “any and every irreverence or distortion.” The document actually only defines the various categories of abuses in the context of laying out their canonical penalties; it gives no reason to think that “any and every irreverence” means “wink wink, just the important ones, I mean let’s be serious here.”
As far as I know, no Church or canonical authority has clarified that the document was intended to create any moral obligation on the faithful at all. Given the obvious impracticability of the plain text, I’d have a tough time figuring that we ought to be guessing ourselves at the lines to be drawn here without some clarification from Rome – particularly if we’re talking about matters of sin rather than good manners.
Needless to say, I’m not a moral theologian either, so don’t take my judgment to the bank just because I said so.