Didn't you watch CW in October 2013 - when they ruled out Tannerman and their focus shifted to Smithman? They showed photos of the father aka Tannerman.
1) Directions
All the exits from 5A were to the west of the fathers flat.
Tannerman was coming from the west, the correct direction for anyone leaving 5A ... But the father and little girl were coming from OC evening creche, directly in the east
Tannerman coming from the opposite direction to the anonymous father. How does that equate to the situation ?
2) Different times too, IIRC
https://youtu.be/OZ8jmdWlB8Y The two images seemed to be of different types of men.
i) Tannerman athletic and casual, youthful looking, fairly long striding (especially in some of the earlier images.) And slicked back, close to the head, straightish hair
ii) The father looking like a professional on holiday; rather stiff and too upright altogether … can you imagine any father with child carrying experienced father carrying his daughter any distance at all, as Jane Tanner witnessed her little girl being carried? With the child across his chest and over both sets of arms? Altogether too exhausting for anyone but Charles Atlas and the father was hardly a Charles Atlas type and probably wouldn't want to be either ! This father had a head full of soft wavy hair.
Very different types and the directions are wrong .
The times too
Sorry, but I think that CI Redwood got this one wrong. I don't think that the father was Janes Tannerman