Wow. work on Corvettes with runflat tires that require special equipment for safety, and not a Hummer tire which requires nothing special. Sounds like the guy had no idea what he was talking about, or afraid his hoist would not hold the weight.
All Corvettes have tire pressure sensors, and those low profile tires means you can easily crack a rim.
His store, he can do what he pleases. (Maybe he was a tree hugger in disguise?)