As for the police incident: officer and 70 year old Vietnamese male.
A lot of unknowns is an understatement.
Excessive of force by the officer: via the officer's body cam and the audio. IMO as a former LEO and a family of LEOs; this officer's voice indicates he (the officer) is agitated, has allowed the 70 year old driver to get to close, or perhaps the officer "drifted in range" was looking for an excuse to "get rough". As the driver was jestering communication with his hands in a casual non threatening manner.
Why didn't the officer ask the younger, possibly relative, present to assist in translating to the 70 year old the nature of the ticket and the procedural options. More often than not younger nationalities comprehend American English better than most Americans. And why too often becomes an ibstant agitator to LEOs working the "streets/highways".
The old man's body language also looked pretty casual and non-aggressive. Furthermore, in some countries its not unusual to gesture with your hands and even to touch the other person while talking to them. I don't see him winding up his hand to hit the officer. It lightly touched the cop, who may have deliberately walked into it.
The cop also put himself in a worse position after "forcibly restraining" the old man. Prior to "restraining" the man the cop was standing and facing both individuals/"potential threats". After "restraining" the old man the cop was on the ground and had his back turned to the young lady (the second "potential threat"). Not only that he had just "forcibly (read violently) restrained" her older relative/accomplice. That would have been her best opportunity to attack him if she felt so inclined. I honestly don't see a rational justification for his actions...
This is a good example of just because something is legal doesn't mean you should do it. Think about it, compared to the general American populace, members of this forum are for the most part very right leaning and pro LE. Yet a number of members here are finding this incident difficult to stomach. Imagine how it looks to most Americans who see this. And then people wonder why more stringent ROE regs get passed, why the defund the police movement grows, etc...