You can even offer to donate $100k to a legit children's charity (not one of his) if he agrees to "honestly" redo his claimed run from Cali to Kansas in the same amount of time, although this time delivering complete video footage (offer to pay for the watch and GoPro). He doesn't have to do a full transcon, it would be up to him to continue. He would have to make it to that fateful location of the video in Emporia in the same number of days or less.
I think that would send a big message and it would be hilarious to see how he responds. How could he turn down hard cash for the kids? How would he ever cover the same daily mileage without riding in the RV? COME ON, MAKE IT HAPPEN!