One should also remember the silly way that Trade Me now "snaps" your search to a category.  Do a search and don't find what you want, check to see which category Trade Me limited your search to, it's probably not what you wanted.

In spirit it is drop shipping, to the customer it looks like drop shipping, it takes as long (if not longer) than drop shiping, the price is as if it is drop shipping. You're a local seller drop shippig in my opinion.  But whatever the case, you need to consult with Trade Me to get their determination.

As you have tracking showing it was delivered, trade me won't do anything.  If he posts negative, ask for tm to remove it, you might get lucky.  He would have to take you to disputes tribunal to do more, and as long as you are a private seller he would not likely win.   In short, don't worry about it. 

Poor form Trade Me, poor form. I can't even see an obvious way to get to the edit your profile details unless you have made a post and so can find that post and click your own name in the post. I had to go digging through my email notifications to find a thread I had participated in to find my post to click my own profile to find the field to edit.

If the purchase is from an in trade seller, you ask the seller to send you a receipt. If the purchase is from a private seller, go to your Won Items https://www.trademe.co.nz/MyTradeMe/Buy/Won.aspx click the listing title, and print that page (or print as a PDF). If you are GST registered you can claim the GST on    1. New items sold by sellers who are GST registered   2. Secondhand items sold by anybody (doesn't matter if they are registered or not)