Neither parties were little angels in their driving.
However the worst that could happen to the first rider would be a citation for crossing the double-yellow, illegal passing, and speeding.
The greater offense is the truck driver for attempted vehicular manslaughter and multiple crossings of the double-yellow, speeding, and traveling the opposite lane.
That had many opportunities for head-on collisions, especially for the several bikes that passed in the opposite direction.
That guy needs to go to jail to chill that temper.
On a related note, a similar situation happened to a friend of mine who was riding in the country by himself. Casually I might add.
An oncoming pickup intentionally swerved into his lane to "prove a point", forcing him to take to the shoulder to avoid a head-on.
He contacted the sheriff's who tried to track the truck owner down, but I don't know if they was successful.
I've had several instances in the same area where a driver will straddle the center-line just to make a point. I just chill and follow. No need to flame the fires of road rage.