More like a rogue actor sending you a truckload of parts that are not what they're supposed to be.
Take for instance the blockchain De Beers (the diamond cartel) says it wants to create to track diamonds. Things like country of origin, quality etc... Tracking diamonds is especially important because you want to make sure that the diamonds you buy are not from a conflict zone, the so-called "blood diamonds".
Now imagine that you have a completely trustless bitcoin-like blockchain to track this. What prevents an African warlord from pretending to be Canadian and create fake entries for its diamonds into the blockchain pretending that they were mined in America? Then he can trade them without issue. The blockchain is unable to detect that a user hasn't the right nationality, nor can it track the physical origin and location of a diamond without having to trust somebody to tell it. Ergo your trustless blockchain is no more valuable than a random file on pastebin.com.
To solve this issue you'd need some trusted certification authority that would audit miners and grant them access to the blockchain once they've asserted that they are who they pretend to be. But if you do this then you have a trusted 3rd party and the blockchain can advantageously be replaced by any regular database of your choice managed by this 3rd party.
You can apply this reasoning to any physical good, from organic produce (how do you make sure that the producer isn't lying about making organic oranges?) to paper rolls (how do you know the producer isn't lying about using sustainable foresting techniques?). You need trusted third parties certifying and controlling these things to weed out cheaters.