This is why you always do a proper shoulder check when changing lanes
This video also shows why passing on the right is illegal in many places. Coming to us from somewhere in Hong Kong is this video showing a pretty typical scene as traffic accelerates hard to get past an accident that has caused a traffic jam. The driver of the camera car is in the right lane, trying to make up some time, when a scooter rider appears to do a brief shoulder check.
The problem is that the rider must not have actually looked, as he pulls in front of the rapidly approaching car. Even though the driver attempts to slow down (you can hear the engine rpm drop and the tires squeal) the car still slams into the scooter. Fortunately, the scooter rider was having a lucky day and appears to have come out of the incident unscathed. The same cannot be said for his scooter!