This happens to be a NAUI instructor, and I'm not sure what the NAUI standards are, but as PADI professional (without quotation marks around it, by the way), I can say that we are only able to report incidents if we have first-hand knowledge of them. We must have been involved directly or have witnessed the incident with our own eyes. We cannot make a report based on hearsay, and what we read on SB is hearsay, regardless of its degree of veracity. I presume that because a report may result in legal issues that NAUI, SSI, and the whole constellation of smaller agencies all have similar guidelines about reporting instructors for standards violations or reporting incidents resulting in injury.
PADI SEAP told my partner that she should have QA'd an instructor at a shop she was working at some years ago on the basis of what she was told by that instructor's student, so it appears they'll not only accept but actually require a QA based on second-hand knowledge. My partner had assumed, too, that she would have to have witnessed the incident, so she just encouraged the student to put in a complaint. PADI's stance then was that having an incident described to you by someone who was involved or witnessed it makes you responsible for initiating a QA.
I'd agree that probably doesn't extend to "I read it on the interwebs," though...