At the top of this thread you posted ebay rules.
"Additionally, family members and individuals living together, WORKING TOGETHER or sharing a computer may not bid on each others items." You clearly state that you were "Marketing the collection"
So it looks as you have gone against ebay rules because you wanted to see this "Go up on Ebay". Am I wrong???
So the Platinum_collection needed a positive feedback to list the collection, and you working with the mysterious person hired to list the auction (Not the guy hired to market it) manufactured a false positive feedback as a "favor".
This does come into play when people question your ethics with other ebay transactions.