I did a very dangerous thing yesterday:
I squeezed past a big truck with a trailer on the left at a roundabout as it was arriving at the roundabout. Now this is a big no-no, vehicles tend to cut corners leaving no room between the vehicle and the kerb. But I thought hey, it's OK just go quickly, so I did. The truckie did get a fright as I popped out from under his trucks nose, so to speak, because he lost his momentum with the gears for a moment or two.
Then just on the other side of the roundabout, there is a pedestrian crossing with lights, I always pop the button before going on so I can cross the road later on with no traffic to contend with. The truckie saw me popping the button and was caught by the light. As he passed me later, (I was already on the other side of the road on a service lane) he screamed something at me.