Mike,
5th ammendment protects you against self incrimination, that would include vidoe shot from your non- motor vehicle, so it's there to help if you need. Truly it should use an encrypted stream protocol for recording, that would hold up in any court under the "expectation of privacy" rule.
I've designed a system for cars very similar, coined "Stop Proof" amongst other things... in essence front and rear black box video recording (plus ability to integrate with automotive/cycle signals to record proper turns, stops, etc and GPS data)... all written out (in encrypted stream) to sdcards ... The video is time/date stamped and recorded as 2 streams (for individual or syncronized playback) - the time/date is required for admission in most courts (under security and surveilance footage rulings) but more importantly... if your followed by police, the car is in the rear frame - providing validation of both the front and rear views... if you have police where you are located who would write a bullshit ticket, this is a solution for you... let them write the illegal or total false ticket.. say nothing. Go to court with videos / records for the judge... All you have to do in most cases is show the officer is not telling the truth and the charges go bye bye...
In either case... I read your opening post then skipped to the last page because I've been through this with motorcycles and eBikes (finally, someone did some dumb shit to me... I had coffee with me thankfully, read on for more info)
Having been riding on 2 wheels since I was about 5 (powered since I was 8) it's been 30 years of 2 wheel experience... While riding motorcyles (specifically sport bikes) I learned quickly there are some people out there who just should be driving... like th guy who was trying to push you out of the way while you were exceeding the speed limit by 5mph.
You know the issue wasn't your speed, he was all about control. People who get angry at eBikes (especially if they go the speed limit) and pull shit like that are total control nuts... every single time.
I've had people do the pull past, horn and profanity and then lock the brakes up *(like every person merging in a volvo, now those cocky bastards piss me off... like, haha you can't hurt me. - nvrmnd). One time I actually crashed into and over the
car ( I can't post what happened that day but dude wasn't using a pencil for about 3 months after) so trust me you could have really been hurt.
I think shooting the finger (alone) shows a great deal of reserve however it doesn't improve your situation, it actually makes the problem worse... what happens the next time (maybe) the asshole is behind you, someone who will act that way is freaking unstable to begin with and a danger to themselves and society and no im not talkin about the ones who pass and beep oce or twice... or call out "asshole", that happens... normal frustration and venting?
In my situation... I copied what I would have done on my sport bike... I always keep a bottle of something (glass on the motorcycle) in my rear webbing for just this purpose. I will (and have) smash the bottle into the window of a jackass like that... while he is behind me and before he becomes a danger... This has the remarkable effect of SCARING THE SHIT out of even the most unstable people and it makes driving difficult but not impossible. Combine with the ability to escape (catch me if you can on the GSXR) quickly.. the bottle is the best thing for motorcycles (don't try convincing me... Ive only had to do this twice in my life... once I should have and was crashed because I didn't have a bottle to do it with)
On an eBike... it's not like you can do 100mph (ok methods) so glass and permanent damage is out - you don't want to enrage them further. When this happened the other day as I said I had a coffee with me (fresh from wawa - two lids so it wouldn't splash)... well I deployed the coffee on their sheild. It worked, they stopped dead in their tracks and pulled off the road... I did report this to the local PD and got the license plate off a security camera from my office (which observes the street) and they were charged with reckless driving.
Point of the story... sometimes the best defense is a good offense and careful planning. You have proof catching ability now with the camera but... I would carry a plastic cappacino bottle in the rear trunk webbing or bottle holder (find a spot) for this purpose (it is my plan to just fill a water bottle up with this crap... water bottle is made weaker by putting in oven a while at lower temps) so that it bursts on impact.).
This will cause no damage but will buy you some time of distraction - remember your on a bike, you can go offroad in narrow places they can't I would suggest the most narrow path directly to the police station!
-Mike