Those traffic signals have nothing to do with the crossings - just traffic flows from other arms of the junction. ie the junction is signal controlled but the crossings are not.

You suggest that "Pedestrians cross when the lights are red", but there is no such time. If they are red for traffic approaching from one arm then they will be green for traffic approaching from a different direction. There is no time allocated for pedestrians at all.

The issue of buttons is entirely irrelevant - the issue is the absence of any signal control of the crossing. There is nothing that a button could request. 

It is the case that some of the crossings only cross a single lane approaching from one direction so there are times when that is held at red. But this still does not constitute a signal controlled crossing. At a signal controlled crossing when the pedestrian signal turns red then the carriageway signal must remain on red long enough for pedestrians to cross - and on puffin crossings this is detected. At these crossings  the traffic may be stopped, but could start at any instant.


