Are tantalizing glimpses significant?

Cyberthrush suggests that if David Sibley reported a low-quality glimpse of an "Ivory-bill", the skeptics would readily accept that the Ivory-bill lives. I completely disagree.

It's been reported publicly that Sibley did, in fact, have "tantalizing glimpses" when he visited the area. I don't think any of the skeptics, Sibley included, places much value on those glimpses. There are many cases of highly-respected birders reporting low-quality sightings to bird records committees, only to have their sightings rejected. That is as it should be.

Even a very large number of brief, low-quality "Ivory-bill" glimpses would mean very little to me.