I am inclined to believe Dia who surely would have more opportunities to have seen some than anyone else. Who wants to believe in a world where there are so many blurry smudges anyway. I think it is more romantic to simply live life and not worry about what happens after.

That said I would not mock anyone who believed they had seen such a thing. I have been in several situations where people have insisted that they saw something and nobody else in the room did. On each occasion the "believers" saw something and the "sceptics" nothing.