You are right, because the signs are, roughly in this position:
1) One way road. 2) Pedestrian crossing, the one the kid is standing on.
3) No pedestrians allowed.
So yes, bikes shouldn't go down that bike lane. If it were an official one they would have changed the road signs to allow it. However I know that's a slow road, so combined with the white line it's probably safe at least during the day. In the night not so much, by direct experience, but bikes were going down there in the forbidden direction anyway.
For "no pedestrians", we have what to my eyes much more sensible: the same sign as the Italian one but with a strike through it [1]
[0]http://st2.depositphotos.com/7458252/11066/i/950/depositphot...
[1]http://www.gettyimages.es/detail/foto/no-pedestrians-in-irel...
As a cyclist, I'm all for making cycling safer, but breaking road laws to achieve that goal is not the right way. That's a one-way street, clearly marked as not a sidewalk and definitely not a bike lane against the one-way street direction. Guerilla bike lane or not, imho it's a stupid and dangerous idea to walk or cycle there, especially in that direction.