Yes, I also find the language strange but I suppose it could be that they genuinely feel they have been wronged and are using subtle threats as a means of getting a good outcome. I have had this happen only one other time but that buyer was a Policeman and he could see the parcel had been tampered with. To be fair to this buyer now, I suppose if he is a frequent online buyer they may not have known which parcel this was until it had been handed over. 

At this point the buyer has not made any demands or nor have they opened a case but perhaps if they are not legit they were hoping we would refund to save our feedback. Sadly when I lodge my parcels they just scan them into the system but I am hoping that they have weighed this at some point in the system.