Feedback all seems ok. I always check a buyers feedback as soon as a sale comes in to see what I may be dealing with. Their feedback for others seems ok, perhaps with a few that might suggest there has been some 'negotiating' but nothing obvious. I agree, I was a little surprised that 1) they mentioned my feedback and that they are not sure how we have that rating, and 2) That they imply that the likely scenario is that we did not put the item in the box, not that it has been tampered with. 

My fear is that the buyer will refuse to take to the Post Office which it seems is an Australia Post requirement nor lodge a Police Report? The hope is that given AP are becoming ever more strict with the dimensions and weight that they are checking each parcel?