Mike's methods in weeding out scammers are harsher than what people are used to or expect. But using the hard knocks method is the only way to catch some people who are manipulative and adept at lying.
People forgive and forget way too easily, giving way to more repeat offenders. Scamming someone by not shipping the promised item, misadvertising, failing to package properly, or lying about any transaction details, should be treated the same as cheating in a relationship. Once you do it you will always have an aura of doubt and second-guessing around you. And the only way to avoid this is to never scam in the first place.
No one is perfect. Personal issues will come up where an item may be slightly late to ship (a week, two maybe in an emergency). Situations may arise where an item just does not match the condition because one person is a collector and the other is "rimm_rs anal" weighing the freaking carts and looking under the microscope. Packaging described as bulletproof can still be run over by a truck or drop-kicked, causing desctruction of a rare or irreplaceable collectible.
The best laid plans of mice and men often go awry. But planning for a successful deal, being honest, and following the golden rule, will lead to a reputation of integrity. And that's the only absolute motive in any transaction.