You almost collided with him on the exit, and he may have thought you we letting him change lane. What he did after however was just unhelpful, and dangerous.
There is absolutely no need to park on a pavement, preventing pedestrian access anywhere, but to do it at a primary school is the most dangerous and stupid place of them all...
Another idiot with a camera.
One day they'll antagonise the wrong person and end up in hospital. Now that's one video I'd love to see.