Why facial recognition failed on the CCTV
Partial
11 Sep: officials had 'good video' and were running facial recognition. Same day the FBI said it failed and released stills instead. Parents then did the ID.
Possible boring answers: angle, sunglasses, cap, compression. Possible interesting answer: the gallery they searched did not contain Robinson. Partial because we know the pipeline failed and the family succeeded; we do not know the gallery.