Wow, I am not sure where to start. I have my opinions and then there is that thing called the law.
In my opinion, the OP aggravated the situation. There is something called defensive driving and decency. The Rooter guy obviously saw you and anticipated at your speed which was 56mph at the time; he thought he could have got in front of you. He could have and should have, but you accelerated up to 70 mph within 30 secs
In his view you cut him off is the worse case perspective, best case perspective you were rude and impolite
By law, you can be rude (you were) and not be ticketed or arrested; but it breeds what is called road rage which the Rooter guy snapped. If I were he I would have been pissed at you too, but I don't have time to deal with pettiness on the highway as he displayed. I would have flown by OP doing 90mph
As far as the video, I think it is more damming to OP than Mr Rooter. If video is sent, as de facto unofficial legal council; I would suggest
removing the 1st 45 secs; so you only show what Mr Rooter did, NOT what he was reacting to
If I were a law enforcement officer with the full 1 minute video, I would issue the following citations.
Mr. Rooter - Ticket for Reckless Driving
Mr. OP - Ticket for Speeding in Excess of 10 mph with aggravating factors RV, Tow vehicle & congested traffic.