So isn't this the answer to all our postulating? He put his bike in his "tow truck" or was towing it..set it up off the truck into the grass. Maybe was standing there with his helmet on..confrontation, she kicked his *advertiser censored**, she was also injured..he puts motorcycle in his truck along with her and takes off. He left his stuff because he was off his game as it didn't go as planned, someone could have been coming, whatever. He tells LE he was on his bike and there are things at the site to prove it plus he covers that his fingerprints are on bike that he left (He was also leaving the bike in the first abduction too!) BOTH the truck and the motor bike were originally at the scene.
You can't tow a motorcycle behind a truck and the tow hooks were on the front. It would be very difficult to load/unload into a truck.