And even if you would, the other guy would not - so you would think, hmm, I split 200 or the other guy just walks off with a necklace and the guy on the phone looses.
So altruistically you try to help the guy on the phone and agree to the deal knowing that otherwise he'll never get his necklace back.
Do people seriously fall for scams like this? There are two glaring red flags in this scenario that were completely lost on the author: 1) The coincidence of someone finding the necklace and another person phoning in about it while the first guy was still in the store, and 2) the first guy asking for cash.
In my experience, coincidence--or any kind of anomaly, really--and strangers asking for money individually should be enough to arouse suspicion. Together they're a dead giveaway.
I find that you should also be wary of people who accept others regardless of their shady behavior. Usually it indicates they are just using everyone around them, as they don't care about moral values.
There's a huge difference between reading about this on the web and actualy being in an emotional situation where you want to help someone and don't diligently think all the consequences through befor you act. A situation also known as everyday life.
"... The key to a con is not that you trust the conman, but that he shows he trusts you ..."
The key to this con, a bait & switch, is greed and deception. Another key is deception. If the person is greedy, they just might be willing to tricked into suspending belief thus making deception easier. It's very hard to con someone who is honest because they aren't looking to gain something for nothing.