You seem to be angry and so defensive about something!
I was associated with the Dept of Transportation for over 35 years. I had the privilege and fortune of many years learning from their seminars and my association the same with the California Hwy Patrol with their ride-along. Although it was never my intention to be riding a motorbike I had the opportunity from my involvement to train to operate a motorbike properly.
In my association with these two organizations, I learned some fundamentals at accident scenes nearly all cadets for law enforcement will be given these basics training to apply to at least determine the cause until the real forensic expert shows up and does their reports. Now living 20 years I seriously doubt the huge majority of police even can figure out 2 plus 2 is 4, sorry if those reading feel this is Thai bashing. In many of the cases, I rode along after listening to the expert you can already develop your assumption which I always kept to myself unless I was asked by the officers I being a guest.
In this particular case, I watch the video and one doesn't have to be there to express an observation from my experience. What do we have you or I will never see the report so what are we left with " Assumption " Here is mine!
Before the vehicle comes into the picture you will notice 3 motorbikes, a single rider, then a sidecar, then another single rider traveling in the opposite direction observe their movement or speed by gauging their surroundings when the vehicle comes into the picture and make the right turn from the video whatever " right away " vehicles coming towards the vehicle had is gone the vehicle has taken 100% and more if one looks at the front vehicle it is over the solid white line on the side of the road. Yes, even in Thailand there is such a thing as " right of way " and there is such a thing it can be taken from observing this Soi the speed limit should be around 30 KM/H with a 10 KM/L lead max of 40 KM/L. Now take a good look when the vehicle has made the right it stops at the solid line the driver in my opinion based on stopping sees the biker coming and freezes thereafter no more than 3 seconds before the biker comes into the picture those 3 seconds add up that his speed was in the range of 50-60.
Compare those three seconds to the previous 3 bikers traveling past this point the same distance. You watch the picture and enter the picture from the video there is no attempt to slow down, avoid, or lay the bike down which is the proper training whenever one knows that is the final alternative. The biker from the video looks like they intentionally decided to just slam into the vehicle on purpose.
Police here have no training. Where I'm from ride along if a first responder officer looking at the accident first attends to the hurt rider then he views the accident and knows within minutes a general picture as to what happened. He will speak to witnesses, the car driver passenger to check and align the stories. then he or she will start the basic forensics, are there any skid marks if so they will be measured, the depth of the dent impact into the vehicle, the distance the biker was thrown, etc., etc.
will determine the speed of the biker.
All this evidence gathered will determine the report which doesn't exist in Thailand from my experience. If this was all done I believe what I saw in the video the forensic report would confirm my assumption. One doesn't need to be there and know when any vehicle is operating well beyond the limits.