I totally get stopping at a junction and giving way to the right on a roundabout but also observe what's ahead of you FFS!!
At this roundabout you can see way before you get to it what is or isn't coming from the right so why you need to be jamming on the brakes so far in advance I have no idea because you were going way under the limit to begin with.
Even after you see there's sod all coming from the right you still come to a total stop. What for?? Some phantom vehicle? Pay attention!!
Arrogant prick in a black transit van too busy texting and drive straight through a red pedestrian traffic light