Maybe that the brake lights don't work or that there was never an attempt to step on the brakes.
The mixer bounced, looked like it was empty.
There is a possibility of a distracted driver which is rampant in Manila. Using a mobile phone whether texting or voice calls are a distraction and are often disastrous. The police should have confiscated the phone if the driver had one on himself or in the transit mixer. If the time stamp of the video clip coincides with the voice call or text from that phone , it is almost certain that the driver was distracted.