That was exactly how that Canada gold heist happened. Thieves had arranged fake documents and the staff helped load $20 million in gold bars onto the truck.
Food fraud is also rampant. Stuff like olive oil is commonly fake or much lower quality than advertised. Its something like 20% of all food items are fraudulent in some way or another.
That is different type of scam though. My favorite is seafood - if you are buying already fileted and it is not salmon or tuna - there is solid chance you won't even get the same species.
Look up the CoolKicks scandal. A sneaker reseller worth tens of millions was caught paying off people at Nike's warehouses to swap shipping labels and get items shipped to them instead. These were unreleased and rare shoes worth millions. It took the FBI months to catch them.
Around 2012 or so a client was building out a bunch of new database servers and had purchased fusion-io cards for them, which I think were going for something like $20k each. Well, the carrier never showed up on the day we were supposed to get them at the DC. I always assumed someone looked up the price, saw $100k+ worth of hardware that could be stuffed in a tote bag and decided to never show up to work again.