Good Lord, you are making this way more complicated than it really is. In a nut shell, yes in a perfect world a sell/buy transaction should go off with out any issues. Honesty, openness, fairness, blah,blah,blah............ Sadly this doesn't always happen. And one should always expect the unexpected and learn to deal with it accordingly. Including getting caused at or yelled at. Again, to be perfectly clear, I don't agree with any buyer getting yelled at or cussed at but it happens. So might as well accept it and deal with it -OR- cry about it on a public forum and still not abtain any resolution.
Clarence, where is the screenshot of the 3 builders that read this thread and agree with you? Where is the signed document from D&D stating the bike had been fully inspected and is ready to sell? It is funny how you have a screenshot for everything, except for your own stories.
I don't spend money to get yelled and cussed at. If that is the anywhere near the norm with you, you need to find new vendors.
Give him awhile. He's busy making up another story and trying to send himself more text from his own fictional characters that in his mind collaborates everything. What a nut jobber. SCREENSHOT
The worst 10% of your customer take a shit load of time. Fire them and then add 10 good ones for each shitty one you get rid of.