Follow-up - As you can see by the owner's response, he takes no responsibility for his own dishonest employees. Their initial estimate was for a full truckload plus as much as another half a load. He claimed there were "30-40" milk crates when in fact there were 15. I sent pictures of them and he claimed there were hidden crates (according to his guys). When I sent him pictures of all angles of the yard and sides of the shed, he had no response.
See my Yelp reviews for other contractors that I've worked with in Phoenix. I've been managing my properties for more than 10 years with no problems. I have no reason to go after a random contractor. He simply has dishonest people working for him and doesn't want to accept that.