Dogs are loose around atv's, farm trucks, cars, horses (!!), (skidoos I have learned lol) all the time... loose. As in they can run in front of it (or in the case of a horse behind it) while it's moving. The guy was holding onto the leash, keeping the dog to the side of the vehicle.
The dog got lots of good exercise at a good pace for a dog. I know Roman would positively love it because he hates walking and I don't like jogging (usually I let him off leash so he can do his own thing). I mean you know how many people are in shape enough to wear a high-energy, conditioned dog out by running with it? Not many I bet.
The guy is practical lol.