I've had similar situations twice before. One I actually put money down on, and when the guy was getting the VIN numbers, and info for the paperwork another buyer came up and told him he'd pay his asking price. He handed me back my deposit, and asked if I'd match the other guy. I didn't even want to do a deal with someone who'd pull that on me.
Another time I agreed to meet a guy to buy a car, and at his asking price, because it was a bargain. The guy called me back a half hour later and asked if I was positive I wanted it, because another guy also wanted it. I affirmed I did, and he said he'd see me tomorrow. Then he calls back in a few minutes and says the other guy offered him more than he was asking, and would I match it? I told him to stuff it where the sun don't shine! Then I asked him if his word was worth so little that he'd sell it for a hundred dollars. His reply was that he saw nothing wrong with getting the most he could out of the sale.
All sorts of flakes and dirtbags around. Hopefully the old guy's problem was just dementia or alzheimers, and not being a sleazebag.

 

Sorry it didn't work out for you Gorn.
On the flipside, flaky "buyers" haven't helped matters either. I can't tell you how many times I've had people on the phone who "want" what I'm selling and will be out tomorrow with the money. Tomorrow came and went too often, which leaves one tired of getting burned by telling others in the meantime that "it's sold". A buyer can be as much of a sleazebag as a seller can be. Past experiences like this makes it awful hard to not take the sure thing, cash in hand buyer.