Took two seconds to find: http://pages.ebay.com/help/pay/methods.html
They really don't want you paying w/ checks or money orders. It even states they aren't allowed for most purchases. The category that Lyman tool was under was most likely not one that is authorized to offer a money order payment option.
Here is some more reading: http://pages.ebay.com/help/policies/...ts-policy.html
http://pages.ebay.com/help/policies/...tml#categories
While a poster went about it the wrong way and sounded like he was trying to pick a fight. You did violate their rules by sending a money order as payment.