Where in the Highway Code does it say you MUST stop if someone is on the pavement and not the crossing? As far as I'm aware there is no legal requirement to stop, the only exception being a driving test. Unless someone physically steps onto the crossing then you should exercise caution and be prepared to stop, if you can. It doesn't mean you have to.
Oh look at that, there was loads of room and he hurt no one....
People make mistakes as to where they need to go, and this guy changed lane without impacting anyone else in any way.
omg is the pedestrian alright?