My hot take:
A seizure for a traffic violation justifies a police investigation of that violation.
That's straight from Ruth Bader Ginsburg's pen. Rodriguez v. United States. United States Supreme Court. April 21, 2015.
So,
1. Was there a traffic violation? Cops sure seem to think so. I bet they win that one.
2. Does that entitle them to "seize" Hill and his vehicle? Seems implicit from RBG's quote.
3. Is an investigation into that violation justified? RBG says so.
What is an "investigation?"
Beyond determining whether to issue a traffic ticket, an officer’s mission includes ordinary inquiries incident to the traffic stop. Typically such inquiries involve checking the driver’s license, determining whether there are outstanding warrants against the driver, and inspecting the automobile’s registration and proof of insurance. These checks serve the same objective as enforcement of the traffic code: ensuring that vehicles on the road are operated safely and responsibly. A warrant check makes it possible to determine whether the apparent traffic violator is wanted for one or more previous traffic offenses.
So, cop gets to check driver's license, check warrants, inspect registration and insurance.
I went back and watched video. First thing that happens when window rolls down is cop notices no seatbelt. Now we're at 2 tickets - speeding and seatbelt.
Then Hill rolls window up. At this point in time, cop still has job to do/right to check driver's license, check warrants, inspect registration and insurance.
You can see Hill in the car moving around and putting on his seatbelt.
Cop tells him to roll down/keep down the window, at least 3 times.
Then Cop tells him to get out of the car at least 5 times before cop 2 opens the door.
Everything goes off the track... cops aren't backing down now.
Noteworthy: Florida state courts have described "refusing commands to roll his window down, unlock his door, and hang up his phone" as "resistance."
If we're arguing the "what should be" in this country, you can throw all of the above out.
If we're debating the "what is," I think the Supremes and Florida court would say
"These cops were on a lawful mission and Hill's refusing commands to roll his window down/exit the car was resistance/obstruction to/of that lawful mission."
I'll let someone else roll out what happens when you resist/obstruct a cop in pursuit of a lawful mission.