Thanks everyone for the input. I didn't realize it was lag, or a quick save. I seen the truck coming in the other direction and assumed the lead truck on my side of the road hit the breaks, but as Francky pointed out, there was no break lights, so he is probably correct.
As someone who generally follows the rules of the road in real life in Canada, and in game, I think two people were at fault:
The truck coming in the opposite direction, he crossed the centre line.
The truck that just finished passing me. He was following too close to the lead truck and did not have time to react. In most driver's handbooks it tells you to maintain proper following distance. He was also speeding. However, it doesn't sound like admins enforce speed limits or following distance.
I wouldn't lay any blame on the lead truck on my side the road, he was reacting to the other truck.
However, all this being said, I posted this video on Saturday. I played on Sunday, and filled up my allowed reports with a single trip. After being rammed multiple times, a trip from Poland to the UK netted me -50K Euros after truck repairs. I have no more room to report this.
Good news, my two trips last night were much less eventful. I have a few people on video who I would say were driving recklessly, and one attempted rammer who missed, but no one made contact with my truck. I avoided the mess that was developing in Scandinavia. I'm currently in Austria. :-)