Not sure if he is a bad businessman but my experience relating to real estate is if I have more han 1 offer on a house I'm selling, I might not take the highest bidder. There are a lot of factors to consider such as contingencies and how solid the buyers finances are. He was obviously eager to sell quickly and justified in his mind that the 3k difference was acceptable to him if that meant the money was going to be delivered immediately.
On another note, I'll always keep 2-3 buyers on the hook and if all three offers are similiar, the first one to come up with the cash, wins. I never let greed get the better part of me because sometimes that greed will bite you in the ass. I say kudos to him for selling and getting what he thought was acceptable to him.
Please keep in mind, I'm just a person looking from he outside and the facts that have been presented. I'm sure there is more to it.
Regardless, good luck to all parties involved and Shap don't sweat it, you will find something else that is bigger and better. You always do
If you have real dollars, contact me and I'll fill you in. You can email me at akalogianis AT jsamedia.net