This feels like a lot of conversation without facts to support it.
“Super-hook’s” are generally known. Child of an actor, best shot-putter in California…these are known. Legacy isn’t that valuable anymore. The one thing folks may not know would be a large donation history or a major donor sponsoring the student. We had an option (unused) to have a family friend who had recently given $10M+ to a school write a recommendation. I can see that helping, but I’m not sure the level needed for Ivy overrides.
The other possibility mentioned is data. It’s difficult to think that the data is wrong, as Naviance is used for a lot of administration by the high schools. The more likely scenario is that the test is an outlier. It’s possible that the studen took the SAT, did poorly, and focused on the ACT (where they performed better). If you sort on the SAT, you’ll see the low score and falsely assume that score means anything. It may never have been submitted anywhere. I would look at the other test scattergram for the GPA, and see if you can “match” the admitted student.