I got a 12 qt box of Supertech from eBay for a few bucks cheaper than I could have bought it for in the store. I had an identical box bought from a real B&M WM and the date code font etc were all matches. They also identically passed the shake-glug test on the coldest winter night I could find. (I was concerned about counterfeit product.)
My theory, naive to the triangle fraud angle, was that WM wanted a parallel distribution for overstock that wasn't undercutting themselves directly. Sort of how Ford sold the #1 sedan, the Taurus, by sending hundreds of thousands to Hertz for a few thousand miles then selling them as used cars.