Nah - I'd give him an F. He's an idiot.
He's overloaded and overbalanced. Exactly the kind of set-up that starts moving around while doing 60 on the interstate. It all goes downhill from there and somebody in the lane next to him gets killed. At best, that's a 3,000# axle. Even without an engine the van and trailer weight will be beyond that. Should have just rented a tow dolly.