I think the light on the bulldozer is just reflection/glare from the light on the building. Cameras can cause a light source (that can clearly be seen above the door of the small building) to glare causing the light ball effect.
As for the large ball of light that moves behind the whole building at first looks like the moon, but why does it change altitude so suddenly? Also bearing in mind that the small light at the front causes so much glare it becomes a large ball could the light source behind actually be smaller? Maybe it looks larger than it is because of the camera glare.