Just don’t buy it in the first place and save everyone time and money. Let’s take people who are veterans in the industry, in area of content production and then ask sound engineers how big their sound assets collections, ask modellers how many texture packs they have, ask a programmer how much code base he accumulated over the years. These assets are suppose to be facilitators of your productive work, not a replacement for it. There are there so that programmer don’t have to get a license for Maya and learn how to model, rig and animate a character over a single weekend for your game prototype.
It’s largely irrelevant if refunded asset gets stolen or not. The problem is with the whole system, where at the end of the day, content creator have to spend his time to build a lengthy argument as to why customer claim is based on unrealistic expectations of what product is actually suppose to do. From what I understood, it’s not a rare occurrence where marketplace team doesn’t have enough qualification to dispel some of the claims themselves and they push them to content creator. With a little bit of math I can tell you that most likely it would be just cheaper to not reply anything at all and just get it refunded, just not to deal anymore with those clients. There are sellers who want to personally forbid some of their customers from purchasing any other of their products, as it cost to seller more to provide tech support to them then what seller makes from sales.
Marketplace creators are asking for a better environment and security of their work, if situation doesn’t improve they will switch shops or leave completely. It might sound bland but either agree with them or replace them, accepting the same rules by which they have to work right now.