UFO Sighting in Cascais, Lisboa on 2012-05-30 15:51:00 – Cigar shape object observed only in the picture

The following exert is an eye witness statement. Please read into it what you will. This has been reported to mufon who I am sure are investigating:

I was taking pictures of this fortress called forte do guincho, near cascais, lisbon.
i didn’t notice the object untill i saw the picture. i took one in the same place less than a minute before and another a minute after and the object does not appear in any of these (before and after).
when i saw it (in the picture) i thought of a cigar shape ufo.
i only can describe it as something clear cigar shape, very high in the sky, grey.
i would like to know what can it be…A plane, an ufo? what do you think about it?
thank you.