Just look at what the rider sitting in front of the camera did to his fellow motorcyclist on his left.
Both were riding underbone motorcycles (you may know these types of affordable bikes under different names in different countries) and were waiting at a traffic light at a busy intersection in Thailand.
With a cunning move, the man wearing the helmet went to troll the other biker (could be his friend) by twisting the throttle a tad, but that had a painful outcome.
Apparently, in an attempt to grab the handlebar brake lever, the rider probably held down the throttle in the same position, which catapulted him in front, first crashing into another bike before falling to the ground.