This place tried the same thing with me. I have a 38' fifer and had installed Sailun G637 on it. While fueling at the station accross the freeway (think it was the BP, but it really doesn't matter), a kid came up and started the same conversation. However, what he didn't know is I have 30 plus years as an aircraft and auto mechanic. I quickly told him to leave, and I left after fueling.
i feel for the folks that get taken advantage of by people like this. They have no conscience, no concern for anyone but themselves. Scammers have always been around, and they will always be. The best defense is to not react out of emotion, but to remove yourself from the situation. Since you were heading to Las Vegas, your next town would be in about 45 miles (Cedar City). IF there were to be a problem (and that is a huge IF), you'd be able to get help there. At Cedar City, if the concern is there, stop at one of the tire shops and ask them. Just like in medical, a second opinion (especially from another town) can normally be trusted. Sadly, Beaver is very small, and I can't remember more than one tire shop, but if there were, the bet goes they are owned by the same person.
The other suggestion I have is when you noted the tires were not what was advertised, a little internet search would have solved it. Since most folks carry a smart phone (or tablet, or laptop), this can be done easily. I would also ask why the tires being installed were not verified by the buyer as being correct. All tires state the load rating, load range, max load and max psi on the sidewall.
I'm not trying to be a ****, but have sadly seen too many folks (to include me and my parents) get zapped by someone or something. Very few things in life require immediate attention, but these types of folks prey on emotions, and emotions are the hardest thing to control. My parents, in the same situation, most likely would have done the same thing as the OP, and my dad wouldn't have done the calls to verify pressures, so he would have had bigger issues.
Hindsite is 20/ 20, and when I make an error, I am harder on myself than anyone else could be, but when I do, try and learn from the mistake. Learn how to educate myself on whatever I made the mistake on. The OP did the best thing possible by spreading the word, but he is now out his time for the replacement of good tires with bad, the time to have the bad ones changed out, plus the cost of getting replacements that are correct. This isn't right, and the shop needs to be held accountable, and that could mean a civil lawsuit for lost time and cost of the second set of tires, pursuing the BBB and consumer affairs complaints (which has been done), and maybe getting the local TV channels involved. Salt Lake City has some good consumer affairs folks on TV, and bad publicity always hurts. The other thing to do is contact Motor Home Life and Trailer Life as a letter. The more folks that are aware and can not be taken, the better.
