A few thoughts.
1. Was the vendor even aware it was gutted or was this an estate sale pick up, untested and just moved along?
The OP said in his video (9:24) that the guys running the booth said it ran.
2. Did the vendor mis represent the item? The buyer said I'll take it. If that was the extent of the exchange then there was no scam
Again, they said it ran and it obviously does not.
3. Not taking a credit card, so what. Its essentially a flea market, cash is king and legal tender.
Credit cards have some options of recourse to recover your money in some of these situations, scammers know this and don't like them for this reason. I don't know about others but I hate carring thousands of dollars around at a show that is easy to lose or steal. They take my credit card, big deal, I'm not responsibile for unauthorized purchases.
4. Reporting to the show? Again, I didnt hear him say it was mis represented, so he was an uninformed buyer.
Watch the whole video and listen carefully at the 9:24 timestamp.
5. Test every powered unit, i sold one once, the buyer came back not pleased with the performance despite my disclosure it would need some tlc, happily refunded his money on the spot. Similarly i bought a 60 trolley once, failed to run on the test track, vendor asked what i wanted to do, got half off and repaired it.
Agreed! Test any powered unit and all of its functions before paying.
6. Sell it as a dummy, recoup part or all of your costs.
Good Idea, It's still a nice looking piece.
7. My pet peeve, why does this generation need to air out everything on social media? Are we supposed to form a posse on his behalf? Work the problem in silence. And it is entirely possible the sellers will be at york. If they are, deal with it discreetly and politely, you might be surprised. In my experience the number of scammers in this hobby are few.
Sometimes people like to tell their story so others can learn and not fall victim to the same situation. Who knows, maybe it helps him with the grieving process of a big let down.