I see the Smiths as reliable witnesses too, but the only thing that reminded Mr Smith of the person he saw with the child was the way Gerry carried his child off the plane, not his features or anything else.
Mr Smith gave two reasonably good descriptions of the man he saw. I expect he had also stored a moving image in his brain on the night. Seeing photos and videos of Gerry McCann had no effect. It was only when he saw him in a very similar situation that the moving image was recalled.
he was Caucasian, around 175 to 180m in height. He appeared to be about 35/40 years old. He had an average build, a bit on the thin side. His hair was short, in a basic male cut, brown in colour. He cannot state if it was dark or lighter in tone. He did not wear glasses and had no beard or moustache.
He was average build, 5 foot 10' in height, brown hair cut short, aged 40 years approximately. Wearing beige trousers and darkish top maybe a jacket or blazer. He had a full head of hair with a tight cut.
He states it was like watching an action replay of the night he saw the male carrying the child back in Portugal. He states the way Gerry was carrying his twin triggered something in his head. It was exactly the same way and look of the male seen the night.... It was the way Gerard McCann turned his head down which was similar to what the individual did on 3rd May 2007 when we met him. It may have been the way he was carrying the child either.
http://www.mccannpjfiles.co.uk/PJ/MARTIN_SMITH.htm