To be fair the thread title does say 'Beginner: Kingfisher Behaviour' then goes on to mention photographing at the nest. I would also assume a person with a shecule 1 licence for kingfishers would not be asking for advice on kngfisher behaviour on talk photography considering you need to know the species behaviour well to be granted a licence.
I think there is a difference between a schedule 1 flying over a house (i.e. Not at a nest!) and a photographer intentionally standing on a footpath photographing a schedule 1 species near a nest for a period of time. Walking along the footpath not knowing where the nest is located is likely to be seen as intentionally disturbing whilst visiting for photography purposes is likely to be seen as intentional.
Schedule 1 isn't something that many are aware of or fully understand, and it's good for it to be raised on TP. Schedule 1 protection says 'Intentionally or recklessly disturb any wild bird listed on Schedule 1 while it is nest building, or at a nest containing eggs or young, or disturb the dependent young of such a bird'. It's interesting to note there isn't a definition of what is 'intentional or reckless disturbance, though I fully expect it's down to the individual to prove they weren't causing disturbance. If you look at what is required to gain a schedule 1 it's likely to need similar experience/qualifications to prove you weren't causing disturbance. Personally it's something I stay away from because of the schedule 1 requirements.
The whole act can be read here:
http://www.legislation.gov.uk/ukpga/1981/69