Clearly your fault. Any good ebay seller must be able to read the minds of any and all potential buyers and anticipate their every need. If any of the potential buyers have trouble reading, it is your duty to personally visit them at their convenience and read the description aloud to them a minimum of 4 times. Clearly this buyer had retina damage and/or color blindness and could not see your clearly marked, all caps, bright TRIMMED. This was clearly your fault - you should have marked the words TRIMMED in at least 20 different colors including salmon, atomic tangerine and burnt sienna.
If you need any tips on writing ebay descriptions, please contact this seller. He know how to cover all his bases.
http://www.ebay.ca/itm/Holy-Smokes-H...item338139de85
Don't give this guy a refund - he clearly can't read!