I only am concerned when a tanker is dumping fuel, when the prices are swinging different directions. Most retail outlets, including gas stations, use the Last In First Out accounting method. That means, the price of the fuel being brought in is the price that is going to be on the pump soon after. When fuel is on the rise, and I see a tanker come in, I will fuel as quickly as possible before he completes the dump. If prices are on a downward trend, I pass on by and come back a little later and top off at the lower fuel price.
If a guy wiped out the fuel system on his Cummins over fuel being stirred up, he had bigger issues than the fuel he bought. Cummins is very meticulous about the fuel filtering on their engines. That owner must have been using a larger than recommended micron filter for the engine, not used the proper filter, poorly maintained his fuel system, or had other issues already going on. I go thru over 21,000 gallons of diesel every year and have taken at least two heavy diesels to over 1 million miles without fuel related issues and have 326,000 miles on my current one. The two I took to over 1 million were both Cummins engines. I fuel from Nebraska to Ohio, even when tankers are dumping. All year round. Even if something got stirred up, the fuel filters on the vehicle should take care of it. Might cause a more frequent filter change, but nothing that got stirred up should ever make it to the engine. Water, crud, nothing but fuel should make it thru the proper filters on a diesel engine.