Here is what I think might have happened:

The guy in the explorer is very familiar with the law. He realizes that the road has a solid double yellow (dis-allowing a vehicle to cross for the sake of passing) and also understood that a three foot buffer zone is required to pass a cyclist. Based upon the law and lane width there was no safe option for a pass. The bikers were unable to travel at or near the posted speed limit. He was trying to have the bikers pull over and offer up the option to pass and continue at the posted speed limit.

While the speed limit is a maximum and not a minimum speed it's very annoying (bike, motorcycle, or car) when you are behind someone traveling significantly slower. We see road rage all the time between two cars for the same reason and it sucks but this situation is no different. Aside from being obnoxious I dont see anything this guy did wrong. Just followed the law in a safe manner.

Also, if bikes ride on the road and don't follow the law they should be issued tickets just the same as if they were in their cars. Those laws are provided for safety of everyone using the roadway.