A big pat on the back to an American kid who had the presence of mind to instill a dash cam in his car. Anyone who has been unfortunate enough to have had any dealings with police will know that this is entirely typical behavior. If the police feel like it, they will charge you with any number of false charges. If you can afford the exorbitant cost of a lawyer, you can do your best to fight them in court but they have the advantage because the courts believe (or pretend to believe the police). If you can't afford it, the crown, knowing that the charges are bogus, will offer you a deal and let you choose a couple of charges that you can plead guilty to. It is generally a no-win situation for you.
Again congrats to the kid who recorded the incident. Watch it and if you have ever said "Well he was charged so there must be something to it, the Police don't go around laying false charges", think again, it happens all the time.