>>I have a tough time believing that false positives would slip through that many layers.
I don't, not in the slightest. Back in the days when Geek Squad had to report any suspicious images found during routine computer repairs, a guy got reported to the police for having child porn, arrested, fired from his job, named in the local newspaper as a pedophile, all before the prosecutor was actually persuaded by the defense attorney to look at these "disgusting pictures".....which turned out to be his own grand children in a pool. Of course he was immediately released but not before the damage to his life was done.
>>But I’m not concerned about a perceptual hash ruining someone’s life
I'm incredibly concerned about this, I don't see how you can not be.