How can you tell whose bat or jersey it really is on the little swatch or bat piece.
Exactly. I wouldn't be too concerned that legit piece got dumped in the blender. Swatch cards are the perfect place to dump bad jerseys, once it becomes apparent that the complete piece has too many red flags to sell in its original state.

I think an infamous eBay seller (MSNBC shill report) was selling swatches a few years back too. I bet the fabric that was supposedly from a coat of one of the Beatles was real too.

One of the most foolish acts in the hobby is taking the word of someone who is trying to sell you something.