The point is:

Who sells a mod has an obligation to support

I bought the mod in the Dolphin Market, so the responsibility and the Dolphin. I do not care who created the mod. When you buy a product in a store if not satisfied with the product you must submit your complaint to the head of the store, not the one who created the product ...

And where is written that the site of the Dolphin is not responsible for products sold in Market?

I do not know Australian laws but here in Europe this see more kind of attitude is reprehensible